Home » Mailing lists » Devel » [PATCH v3 00/28] kmem limitation for memcg
| [PATCH v3 00/28] kmem limitation for memcg [message #46517] |
Fri, 25 May 2012 13:03  |
Glauber Costa
Messages: 916
Registered: October 2011
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Senior Member |
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Hello All,
This is my new take for the memcg kmem accounting. This should merge
all of the previous comments from you, plus fix a bunch of bugs.
At this point, I consider the series pretty mature. Since last submission
2 weeks ago, I focused on broadening the testing coverage. Some bugs were
fixed, but that of course doesn't mean no bugs exist.
I believe some of the early patches here are already in some trees around.
I don't know who should pick this, so if everyone agrees with what's in here,
please just ack them and tell me which tree I should aim for (-mm? Hocko's?)
and I'll rebase it.
I should point out again that most, if not all, of the code in the caches
are wrapped in static_key areas, meaning they will be completely patched out
until the first limit is set. Enabling and disabling of static_keys incorporate
the last fixes for sock memcg, and should be pretty robust.
I also put a lot of effort, as you will all see, in the proper separation
of the patches, so the review process is made as easy as the complexity of
the work allows to.
[ v3 ]
* fixed lockdep bugs in slab (ordering of get_online_cpus() vs slab_mutex)
* improved style in slab and slub with less #ifdefs in-code
* tested and fixed hierarchical accounting (memcg: propagate kmem limiting...)
* some more small bug fixes
* No longer using res_counter_charge_nofail for GFP_NOFAIL submissions. Those
go to the root memcg directly.
* reordered tests in mem_cgroup_get_kmem_cache so we exit even earlier for
tasks in root memcg
* no more memcg state for slub initialization
* do_tune_cpucache will always (only after FULL) propagate to children when
they exist.
* slab itself will destroy the kmem_cache string for chained caches, so we
don't need to bother with consistency between them.
* other minor issues
[ v2 ]
* memcgs can be properly removed.
* We are not charging based on current->mm->owner instead of current
* kmem_large allocations for slub got some fixes, specially for the free case
* A cache that is registered can be properly removed (common module case)
even if it spans memcg children. Slab had some code for that, now it works
well with both
* A new mechanism for skipping allocations is proposed (patch posted
separately already). Now instead of having kmalloc_no_account, we mark
a region as non-accountable for memcg.
Glauber Costa (25):
slab: move FULL state transition to an initcall
memcg: Always free struct memcg through schedule_work()
slab: rename gfpflags to allocflags
slab: use obj_size field of struct kmem_cache when not debugging
memcg: change defines to an enum
res_counter: don't force return value checking in
res_counter_charge_nofail
kmem slab accounting basic infrastructure
slab/slub: struct memcg_params
slub: consider a memcg parameter in kmem_create_cache
slab: pass memcg parameter to kmem_cache_create
slub: create duplicate cache
slab: create duplicate cache
slub: always get the cache from its page in kfree
memcg: kmem controller charge/uncharge infrastructure
skip memcg kmem allocations in specified code regions
slub: charge allocation to a memcg
slab: per-memcg accounting of slab caches
memcg: disable kmem code when not in use.
memcg: destroy memcg caches
memcg/slub: shrink dead caches
slab: Track all the memcg children of a kmem_cache.
slub: create slabinfo file for memcg
slub: track all children of a kmem cache
memcg: propagate kmem limiting information to children
Documentation: add documentation for slab tracker for memcg
Suleiman Souhlal (3):
memcg: Make it possible to use the stock for more than one page.
memcg: Reclaim when more than one page needed.
memcg: Per-memcg memory.kmem.slabinfo file.
Documentation/cgroups/memory.txt | 33 ++
include/linux/memcontrol.h | 101 +++++
include/linux/res_counter.h | 2 +-
include/linux/sched.h | 1 +
include/linux/slab.h | 32 ++
include/linux/slab_def.h | 79 ++++-
include/linux/slub_def.h | 68 +++-
init/Kconfig | 2 +-
mm/memcontrol.c | 897 ++++++++++++++++++++++++++++++++++++--
mm/slab.c | 423 +++++++++++++++---
mm/slub.c | 282 +++++++++++-
11 files changed, 1787 insertions(+), 133 deletions(-)
--
1.7.7.6
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| [PATCH v3 02/28] memcg: Always free struct memcg through schedule_work() [message #46518 is a reply to message #46517] |
Fri, 25 May 2012 13:03  |
Glauber Costa
Messages: 916
Registered: October 2011
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Senior Member |
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Right now we free struct memcg with kfree right after a
rcu grace period, but defer it if we need to use vfree() to get
rid of that memory area. We do that by need, because we need vfree
to be called in a process context.
This patch unifies this behavior, by ensuring that even kfree will
happen in a separate thread. The goal is to have a stable place to
call the upcoming jump label destruction function outside the realm
of the complicated and quite far-reaching cgroup lock (that can't be
held when calling neither the cpu_hotplug.lock nor the jump_label_mutex)
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Tejun Heo <tj@kernel.org>
CC: Li Zefan <lizefan@huawei.com>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Michal Hocko <mhocko@suse.cz>
---
mm/memcontrol.c | 24 +++++++++++++-----------
1 files changed, 13 insertions(+), 11 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 932a734..0b4b4c8 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -245,8 +245,8 @@ struct mem_cgroup {
*/
struct rcu_head rcu_freeing;
/*
- * But when using vfree(), that cannot be done at
- * interrupt time, so we must then queue the work.
+ * We also need some space for a worker in deferred freeing.
+ * By the time we call it, rcu_freeing is not longer in use.
*/
struct work_struct work_freeing;
};
@@ -4826,23 +4826,28 @@ out_free:
}
/*
- * Helpers for freeing a vzalloc()ed mem_cgroup by RCU,
+ * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU,
* but in process context. The work_freeing structure is overlaid
* on the rcu_freeing structure, which itself is overlaid on memsw.
*/
-static void vfree_work(struct work_struct *work)
+static void free_work(struct work_struct *work)
{
struct mem_cgroup *memcg;
+ int size = sizeof(struct mem_cgroup);
memcg = container_of(work, struct mem_cgroup, work_freeing);
- vfree(memcg);
+ if (size < PAGE_SIZE)
+ kfree(memcg);
+ else
+ vfree(memcg);
}
-static void vfree_rcu(struct rcu_head *rcu_head)
+
+static void free_rcu(struct rcu_head *rcu_head)
{
struct mem_cgroup *memcg;
memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing);
- INIT_WORK(&memcg->work_freeing, vfree_work);
+ INIT_WORK(&memcg->work_freeing, free_work);
schedule_work(&memcg->work_freeing);
}
@@ -4868,10 +4873,7 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg)
free_mem_cgroup_per_zone_info(memcg, node);
free_percpu(memcg->stat);
- if (sizeof(struct mem_cgroup) < PAGE_SIZE)
- kfree_rcu(memcg, rcu_freeing);
- else
- call_rcu(&memcg->rcu_freeing, vfree_rcu);
+ call_rcu(&memcg->rcu_freeing, free_rcu);
}
static void mem_cgroup_get(struct mem_cgroup *memcg)
--
1.7.7.6
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| [PATCH v3 09/28] kmem slab accounting basic infrastructure [message #46519 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
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Senior Member |
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This patch adds the basic infrastructure for the accounting of the slab
caches. To control that, the following files are created:
* memory.kmem.usage_in_bytes
* memory.kmem.limit_in_bytes
* memory.kmem.failcnt
* memory.kmem.max_usage_in_bytes
They have the same meaning of their user memory counterparts. They reflect
the state of the "kmem" res_counter.
The code is not enabled until a limit is set. This can be tested by the flag
"kmem_accounted". This means that after the patch is applied, no behavioral
changes exists for whoever is still using memcg to control their memory usage.
We always account to both user and kernel resource_counters. This effectively
means that an independent kernel limit is in place when the limit is set
to a lower value than the user memory. A equal or higher value means that the
user limit will always hit first, meaning that kmem is effectively unlimited.
People who want to track kernel memory but not limit it, can set this limit
to a very high number (like RESOURCE_MAX - 1page - that no one will ever hit,
or equal to the user memory)
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Michal Hocko <mhocko@suse.cz>
CC: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
---
mm/memcontrol.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 77 insertions(+), 1 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 789ca5a..b6bac5f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -252,6 +252,10 @@ struct mem_cgroup {
};
/*
+ * the counter to account for kernel memory usage.
+ */
+ struct res_counter kmem;
+ /*
* Per cgroup active and inactive list, similar to the
* per zone LRU lists.
*/
@@ -266,6 +270,7 @@ struct mem_cgroup {
* Should the accounting and control be hierarchical, per subtree?
*/
bool use_hierarchy;
+ bool kmem_accounted;
bool oom_lock;
atomic_t under_oom;
@@ -378,6 +383,7 @@ enum res_type {
_MEM,
_MEMSWAP,
_OOM_TYPE,
+ _KMEM,
};
#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
@@ -1470,6 +1476,10 @@ done:
res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
+ printk(KERN_INFO "kmem: usage %llukB, limit %llukB, failcnt %llu\n",
+ res_counter_read_u64(&memcg->kmem, RES_USAGE) >> 10,
+ res_counter_read_u64(&memcg->kmem, RES_LIMIT) >> 10,
+ res_counter_read_u64(&memcg->kmem, RES_FAILCNT));
}
/*
@@ -3914,6 +3924,11 @@ static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft,
else
val = res_counter_read_u64(&memcg->memsw, name);
break;
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ case _KMEM:
+ val = res_counter_read_u64(&memcg->kmem, name);
+ break;
+#endif
default:
BUG();
}
@@ -3951,8 +3966,26 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
break;
if (type == _MEM)
ret = mem_cgroup_resize_limit(memcg, val);
- else
+ else if (type == _MEMSWAP)
ret = mem_cgroup_resize_memsw_limit(memcg, val);
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ else if (type == _KMEM) {
+ ret = res_counter_set_limit(&memcg->kmem, val);
+ if (ret)
+ break;
+ /*
+ * Once enabled, can't be disabled. We could in theory
+ * disable it if we haven't yet created any caches, or
+ * if we can shrink them all to death.
+ *
+ * But it is not worth the trouble
+ */
+ if (!memcg->kmem_accounted && val != RESOURCE_MAX)
+ memcg->kmem_accounted = true;
+ }
+#endif
+ else
+ return -EINVAL;
break;
case RES_SOFT_LIMIT:
ret = res_counter_memparse_write_strategy(buffer, &val);
@@ -4017,12 +4050,20 @@ static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
case RES_MAX_USAGE:
if (type == _MEM)
res_counter_reset_max(&memcg->res);
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ else if (type == _KMEM)
+ res_counter_reset_max(&memcg->kmem);
+#endif
else
res_counter_reset_max(&memcg->memsw);
break;
case RES_FAILCNT:
if (type == _MEM)
res_counter_reset_failcnt(&memcg->res);
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ else if (type == _KMEM)
+ res_counter_reset_failcnt(&memcg->kmem);
+#endif
else
res_counter_reset_failcnt(&memcg->memsw);
break;
@@ -4647,6 +4688,33 @@ static int mem_control_numa_stat_open(struct inode *unused, struct file *file)
#endif /* CONFIG_NUMA */
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+static struct cftype kmem_cgroup_files[] = {
+ {
+ .name = "kmem.limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
+ .write_string = mem_cgroup_write,
+ .read = mem_cgroup_read,
+ },
+ {
+ .name = "kmem.usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
+ .read = mem_cgroup_read,
+ },
+ {
+ .name = "kmem.failcnt",
+ .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT),
+ .trigger = mem_cgroup_reset,
+ .read = mem_cgroup_read,
+ },
+ {
+ .name = "kmem.max_usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE),
+ .trigger = mem_cgroup_reset,
+ .read = mem_cgroup_read,
+ },
+ {},
+};
+
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
return mem_cgroup_sockets_init(memcg, ss);
@@ -4981,6 +5049,12 @@ mem_cgroup_create(struct cgroup *cont)
int cpu;
enable_swap_cgroup();
parent = NULL;
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys,
+ kmem_cgroup_files));
+#endif
+
if (mem_cgroup_soft_limit_tree_init())
goto free_out;
root_mem_cgroup = memcg;
@@ -4999,6 +5073,7 @@ mem_cgroup_create(struct cgroup *cont)
if (parent && parent->use_hierarchy) {
res_counter_init(&memcg->res, &parent->res);
res_counter_init(&memcg->memsw, &parent->memsw);
+ res_counter_init(&memcg->kmem, &parent->kmem);
/*
* We increment refcnt of the parent to ensure that we can
* safely access it on res_counter_charge/uncharge.
@@ -5009,6 +5084,7 @@ mem_cgroup_create(struct cgroup *cont)
} else {
res_counter_init(&memcg->res, NULL);
res_counter_init(&memcg->memsw, NULL);
+ res_counter_init(&memcg->kmem, NULL);
}
memcg->last_scanned_node = MAX_NUMNODES;
INIT_LIST_HEAD(&memcg->oom_notify);
--
1.7.7.6
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| [PATCH v3 08/28] res_counter: don't force return value checking in res_counter_charge_nofail [message #46520 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
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Senior Member |
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Since we will succeed with the allocation no matter what, there
isn't the need to use __must_check with it. It can very well
be optional.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Michal Hocko <mhocko@suse.cz>
---
include/linux/res_counter.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h
index da81af0..f7621cf 100644
--- a/include/linux/res_counter.h
+++ b/include/linux/res_counter.h
@@ -119,7 +119,7 @@ int __must_check res_counter_charge_locked(struct res_counter *counter,
unsigned long val);
int __must_check res_counter_charge(struct res_counter *counter,
unsigned long val, struct res_counter **limit_fail_at);
-int __must_check res_counter_charge_nofail(struct res_counter *counter,
+int res_counter_charge_nofail(struct res_counter *counter,
unsigned long val, struct res_counter **limit_fail_at);
/*
--
1.7.7.6
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| [PATCH v3 03/28] slab: rename gfpflags to allocflags [message #46521 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
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Senior Member |
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A consistent name with slub saves us an acessor function.
In both caches, this field represents the same thing. We would
like to use it from the mem_cgroup code.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
---
include/linux/slab_def.h | 2 +-
mm/slab.c | 10 +++++-----
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index fbd1117..d41effe 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -39,7 +39,7 @@ struct kmem_cache {
unsigned int gfporder;
/* force GFP flags, e.g. GFP_DMA */
- gfp_t gfpflags;
+ gfp_t allocflags;
size_t colour; /* cache colouring range */
unsigned int colour_off; /* colour offset */
diff --git a/mm/slab.c b/mm/slab.c
index 8658d72..1057a32 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1798,7 +1798,7 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
flags |= __GFP_COMP;
#endif
- flags |= cachep->gfpflags;
+ flags |= cachep->allocflags;
if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
flags |= __GFP_RECLAIMABLE;
@@ -2508,9 +2508,9 @@ kmem_cache_create (const char *name, size_t size, size_t align,
cachep->colour = left_over / cachep->colour_off;
cachep->slab_size = slab_size;
cachep->flags = flags;
- cachep->gfpflags = 0;
+ cachep->allocflags = 0;
if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
- cachep->gfpflags |= GFP_DMA;
+ cachep->allocflags |= GFP_DMA;
cachep->buffer_size = size;
cachep->reciprocal_buffer_size = reciprocal_value(size);
@@ -2857,9 +2857,9 @@ static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
{
if (CONFIG_ZONE_DMA_FLAG) {
if (flags & GFP_DMA)
- BUG_ON(!(cachep->gfpflags & GFP_DMA));
+ BUG_ON(!(cachep->allocflags & GFP_DMA));
else
- BUG_ON(cachep->gfpflags & GFP_DMA);
+ BUG_ON(cachep->allocflags & GFP_DMA);
}
}
--
1.7.7.6
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| [PATCH v3 01/28] slab: move FULL state transition to an initcall [message #46522 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
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Senior Member |
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During kmem_cache_init_late(), we transition to the LATE state,
and after some more work, to the FULL state, its last state
This is quite different from slub, that will only transition to
its last state (SYSFS), in a (late)initcall, after a lot more of
the kernel is ready.
This means that in slab, we have no way to taking actions dependent
on the initialization of other pieces of the kernel that are supposed
to start way after kmem_init_late(), such as cgroups initialization.
To achieve more consistency in this behavior, that patch only
transitions to the LATE state in kmem_init_late. In my analysis,
setup_cpu_cache() should be happy to test for >= LATE, instead of
== FULL. It also has passed some tests I've made.
We then only mark FULL state after the reap timers are in place,
meaning that no further setup is expected.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: David Rientjes <rientjes@google.com>
---
mm/slab.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/mm/slab.c b/mm/slab.c
index e901a36..8658d72 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1695,9 +1695,6 @@ void __init kmem_cache_init_late(void)
BUG();
mutex_unlock(&cache_chain_mutex);
- /* Done! */
- g_cpucache_up = FULL;
-
/*
* Register a cpu startup notifier callback that initializes
* cpu_cache_get for all new cpus
@@ -1727,6 +1724,9 @@ static int __init cpucache_init(void)
*/
for_each_online_cpu(cpu)
start_cpu_timer(cpu);
+
+ /* Done! */
+ g_cpucache_up = FULL;
return 0;
}
__initcall(cpucache_init);
@@ -2194,7 +2194,7 @@ static size_t calculate_slab_order(struct kmem_cache *cachep,
static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
{
- if (g_cpucache_up == FULL)
+ if (g_cpucache_up >= LATE)
return enable_cpucache(cachep, gfp);
if (g_cpucache_up == NONE) {
--
1.7.7.6
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| [PATCH v3 18/28] slub: charge allocation to a memcg [message #46523 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
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This patch charges allocation of a slab object to a particular
memcg.
The cache is selected with mem_cgroup_get_kmem_cache(),
which is the biggest overhead we pay here, because
it happens at all allocations. However, other than forcing
a function call, this function is not very expensive, and
try to return as soon as we realize we are not a memcg cache.
The charge/uncharge functions are heavier, but are only called
for new page allocations.
The kmalloc_no_account variant is patched so the base
function is used and we don't even try to do cache
selection.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Suleiman Souhlal <suleiman@google.com>
---
include/linux/slub_def.h | 39 ++++++++++++++++++---
mm/slub.c | 87 +++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 112 insertions(+), 14 deletions(-)
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index f822ca2..ba9c68b 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -13,6 +13,8 @@
#include <linux/kobject.h>
#include <linux/kmemleak.h>
+#include <linux/memcontrol.h>
+#include <linux/mm.h>
enum stat_item {
ALLOC_FASTPATH, /* Allocation from cpu slab */
@@ -228,27 +230,54 @@ static __always_inline int kmalloc_index(size_t size)
* This ought to end up with a global pointer to the right cache
* in kmalloc_caches.
*/
-static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
+static __always_inline struct kmem_cache *kmalloc_slab(gfp_t flags, size_t size)
{
+ struct kmem_cache *s;
int index = kmalloc_index(size);
if (index == 0)
return NULL;
- return kmalloc_caches[index];
+ s = kmalloc_caches[index];
+
+ rcu_read_lock();
+ s = mem_cgroup_get_kmem_cache(s, flags);
+ rcu_read_unlock();
+
+ return s;
}
void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
void *__kmalloc(size_t size, gfp_t flags);
static __always_inline void *
-kmalloc_order(size_t size, gfp_t flags, unsigned int order)
+kmalloc_order_base(size_t size, gfp_t flags, unsigned int order)
{
void *ret = (void *) __get_free_pages(flags | __GFP_COMP, order);
kmemleak_alloc(ret, size, 1, flags);
return ret;
}
+static __always_inline void *
+kmalloc_order(size_t size, gfp_t flags, unsigned int order)
+{
+ void *ret = NULL;
+ struct page *page;
+
+ ret = kmalloc_order_base(size, flags, order);
+ if (!ret)
+ return ret;
+
+ page = virt_to_head_page(ret);
+
+ if (!mem_cgroup_new_kmem_page(page, flags)) {
+ put_page(page);
+ return NULL;
+ }
+
+ return ret;
+}
+
/**
* Calling this on allocated memory will check that the memory
* is expected to be in use, and print warnings if not.
@@ -293,7 +322,7 @@ static __always_inline void *kmalloc(size_t size, gfp_t flags)
return kmalloc_large(size, flags);
if (!(flags & SLUB_DMA)) {
- struct kmem_cache *s = kmalloc_slab(size);
+ struct kmem_cache *s = kmalloc_slab(flags, size);
if (!s)
return ZERO_SIZE_PTR;
@@ -326,7 +355,7 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
{
if (__builtin_constant_p(size) &&
size <= SLUB_MAX_SIZE && !(flags & SLUB_DMA)) {
- struct kmem_cache *s = kmalloc_slab(size);
+ struct kmem_cache *s = kmalloc_slab(flags, size);
if (!s)
return ZERO_SIZE_PTR;
diff --git a/mm/slub.c b/mm/slub.c
index 640872f..730e69f 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1283,11 +1283,39 @@ static inline struct page *alloc_slab_page(gfp_t flags, int node,
return alloc_pages_exact_node(node, flags, order);
}
+static inline unsigned long size_in_bytes(unsigned int order)
+{
+ return (1 << order) << PAGE_SHIFT;
+}
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+static void kmem_cache_inc_ref(struct kmem_cache *s)
+{
+ if (s->memcg_params.memcg)
+ atomic_inc(&s->memcg_params.refcnt);
+}
+static void kmem_cache_drop_ref(struct kmem_cache *s)
+{
+ if (s->memcg_params.memcg)
+ atomic_dec(&s->memcg_params.refcnt);
+}
+#else
+static inline void kmem_cache_inc_ref(struct kmem_cache *s)
+{
+}
+static inline void kmem_cache_drop_ref(struct kmem_cache *s)
+{
+}
+#endif
+
+
+
static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
{
- struct page *page;
+ struct page *page = NULL;
struct kmem_cache_order_objects oo = s->oo;
gfp_t alloc_gfp;
+ unsigned int memcg_allowed = oo_order(oo);
flags &= gfp_allowed_mask;
@@ -1296,13 +1324,29 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
flags |= s->allocflags;
- /*
- * Let the initial higher-order allocation fail under memory pressure
- * so we fall-back to the minimum order allocation.
- */
- alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL;
+ memcg_allowed = oo_order(oo);
+ if (!mem_cgroup_charge_slab(s, flags, size_in_bytes(memcg_allowed))) {
+
+ memcg_allowed = oo_order(s->min);
+ if (!mem_cgroup_charge_slab(s, flags,
+ size_in_bytes(memcg_allowed))) {
+ if (flags & __GFP_WAIT)
+ local_irq_disable();
+ return NULL;
+ }
+ }
+
+ if (memcg_allowed == oo_order(oo)) {
+ /*
+ * Let the initial higher-order allocation fail under memory
+ * pressure so we fall-back to the minimum order allocation.
+ */
+ alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) &
+ ~__GFP_NOFAIL;
+
+ page = alloc_slab_page(alloc_gfp, node, oo);
+ }
- page = alloc_slab_page(alloc_gfp, node, oo);
if (unlikely(!page)) {
oo = s->min;
/*
@@ -1313,13 +1357,25 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
if (page)
stat(s, ORDER_FALLBACK);
+ /*
+ * We reserved more than we used, time to give it back
+ */
+ if (page && memcg_allowed != oo_order(oo)) {
+ unsigned long delta;
+ delta = memcg_allowed - oo_order(oo);
+ mem_cgroup_uncharge_slab(s, size_in_bytes(delta));
+ }
}
if (flags & __GFP_WAIT)
local_irq_disable();
- if (!page)
+ if (!page) {
+ mem_cgroup_uncharge_slab(s, size_in_bytes(memcg_allowed));
return NULL;
+ }
+
+ kmem_cache_inc_ref(s);
if (kmemcheck_enabled
&& !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
@@ -1419,6 +1475,9 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
if (current->reclaim_state)
current->reclaim_state->reclaimed_slab += pages;
__free_pages(page, order);
+
+ mem_cgroup_uncharge_slab(s, (1 << order) << PAGE_SHIFT);
+ kmem_cache_drop_ref(s);
}
#define need_reserve_slab_rcu \
@@ -2310,6 +2369,9 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
if (slab_pre_alloc_hook(s, gfpflags))
return NULL;
+ rcu_read_lock();
+ s = mem_cgroup_get_kmem_cache(s, gfpflags);
+ rcu_read_unlock();
redo:
/*
@@ -3372,9 +3434,15 @@ static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
flags |= __GFP_COMP | __GFP_NOTRACK;
page = alloc_pages_node(node, flags, get_order(size));
- if (page)
+ if (!page)
+ goto out;
+
+ if (!mem_cgroup_new_kmem_page(page, flags))
+ put_page(page);
+ else
ptr = page_address(page);
+out:
kmemleak_alloc(ptr, size, 1, flags);
return ptr;
}
@@ -3476,6 +3544,7 @@ void kfree(const void *x)
if (unlikely(!PageSlab(page))) {
BUG_ON(!PageCompound(page));
kmemleak_free(x);
+ mem_cgroup_free_kmem_page(page);
put_page(page);
return;
}
--
1.7.7.6
|
|
|
|
| [PATCH v3 20/28] memcg: disable kmem code when not in use. [message #46524 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
We can use jump labels to patch the code in or out
when not used.
Because the assignment: memcg->kmem_accounted = true
is done after the jump labels increment, we guarantee
that the root memcg will always be selected until
all call sites are patched (see mem_cgroup_kmem_enabled).
This guarantees that no mischarges are applied.
Jump label decrement happens when the last reference
count from the memcg dies. This will only happen when
the caches are all dead.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Suleiman Souhlal <suleiman@google.com>
---
include/linux/memcontrol.h | 4 +++-
mm/memcontrol.c | 22 +++++++++++++++++++++-
2 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index fbc5ba1..bad8ebd 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -22,6 +22,7 @@
#include <linux/cgroup.h>
#include <linux/vm_event_item.h>
#include <linux/hardirq.h>
+#include <linux/jump_label.h>
struct mem_cgroup;
struct page_cgroup;
@@ -460,7 +461,8 @@ void __mem_cgroup_free_kmem_page(struct page *page);
struct kmem_cache *
__mem_cgroup_get_kmem_cache(struct kmem_cache *cachep, gfp_t gfp);
-#define mem_cgroup_kmem_on 1
+extern struct static_key mem_cgroup_kmem_enabled_key;
+#define mem_cgroup_kmem_on static_key_false(&mem_cgroup_kmem_enabled_key)
#else
static inline void mem_cgroup_register_cache(struct mem_cgroup *memcg,
struct kmem_cache *s)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f3a3812..f2f1525 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -422,6 +422,10 @@ static void mem_cgroup_put(struct mem_cgroup *memcg);
#include <net/sock.h>
#include <net/ip.h>
+struct static_key mem_cgroup_kmem_enabled_key;
+/* so modules can inline the checks */
+EXPORT_SYMBOL(mem_cgroup_kmem_enabled_key);
+
static bool mem_cgroup_is_root(struct mem_cgroup *memcg);
static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, s64 delta);
static void memcg_uncharge_kmem(struct mem_cgroup *memcg, s64 delta);
@@ -468,6 +472,12 @@ void sock_release_memcg(struct sock *sk)
}
}
+static void disarm_static_keys(struct mem_cgroup *memcg)
+{
+ if (memcg->kmem_accounted)
+ static_key_slow_dec(&mem_cgroup_kmem_enabled_key);
+}
+
#ifdef CONFIG_INET
struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
{
@@ -843,6 +853,10 @@ static void memcg_slab_init(struct mem_cgroup *memcg)
for (i = 0; i < MAX_KMEM_CACHE_TYPES; i++)
memcg->slabs[i] = NULL;
}
+#else
+static inline void disarm_static_keys(struct mem_cgroup *memcg)
+{
+}
#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
static void drain_all_stock_async(struct mem_cgroup *memcg);
@@ -4362,8 +4376,13 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
*
* But it is not worth the trouble
*/
- if (!memcg->kmem_accounted && val != RESOURCE_MAX)
+ mutex_lock(&set_limit_mutex);
+ if (!memcg->kmem_accounted && val != RESOURCE_MAX
+ && !memcg->kmem_accounted) {
+ static_key_slow_inc(&mem_cgroup_kmem_enabled_key);
memcg->kmem_accounted = true;
+ }
+ mutex_unlock(&set_limit_mutex);
}
#endif
else
@@ -5297,6 +5316,7 @@ static void free_work(struct work_struct *work)
int size = sizeof(struct mem_cgroup);
memcg = container_of(work, struct mem_cgroup, work_freeing);
+ disarm_static_keys(memcg);
if (size < PAGE_SIZE)
kfree(memcg);
else
--
1.7.7.6
|
|
|
|
| [PATCH v3 22/28] memcg/slub: shrink dead caches [message #46525 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
In the slub allocator, when the last object of a page goes away, we
don't necessarily free it - there is not necessarily a test for empty
page in any slab_free path.
This means that when we destroy a memcg cache that happened to be empty,
those caches may take a lot of time to go away: removing the memcg
reference won't destroy them - because there are pending references,
and the empty pages will stay there, until a shrinker is called upon
for any reason.
This patch marks all memcg caches as dead. kmem_cache_shrink is called
for the ones who are not yet dead - this will force internal cache
reorganization, and then all references to empty pages will be removed.
An unlikely branch is used to make sure this case does not affect
performance in the usual slab_free path.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Suleiman Souhlal <suleiman@google.com>
---
include/linux/slab.h | 4 +++
include/linux/slub_def.h | 8 +++++++
mm/memcontrol.c | 49 +++++++++++++++++++++++++++++++++++++++++++--
mm/slub.c | 1 +
4 files changed, 59 insertions(+), 3 deletions(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index c81a5d3..25f073e 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -154,10 +154,14 @@ unsigned int kmem_cache_size(struct kmem_cache *);
#endif
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+#include <linux/workqueue.h>
+
struct mem_cgroup_cache_params {
struct mem_cgroup *memcg;
int id;
atomic_t refcnt;
+ bool dead;
+ struct work_struct cache_shrinker;
#ifdef CONFIG_SLAB
/* Original cache parameters, used when creating a memcg cache */
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index ba9c68b..c1428ee 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -135,6 +135,14 @@ static inline bool slab_is_parent(struct kmem_cache *s,
#endif
}
+static inline void kmem_cache_verify_dead(struct kmem_cache *cachep)
+{
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ if (unlikely(cachep->memcg_params.dead))
+ schedule_work(&cachep->memcg_params.cache_shrinker);
+#endif
+}
+
/*
* Kmalloc subsystem.
*/
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e2ba527..e2576c5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -520,7 +520,7 @@ char *mem_cgroup_cache_name(struct mem_cgroup *memcg, struct kmem_cache *cachep)
BUG_ON(dentry == NULL);
- name = kasprintf(GFP_KERNEL, "%s(%d:%s)",
+ name = kasprintf(GFP_KERNEL, "%s(%d:%s)dead",
cachep->name, css_id(&memcg->css), dentry->d_name.name);
return name;
@@ -557,11 +557,24 @@ void mem_cgroup_release_cache(struct kmem_cache *cachep)
ida_simple_remove(&cache_types, cachep->memcg_params.id);
}
+static void cache_shrinker_work_func(struct work_struct *work)
+{
+ struct mem_cgroup_cache_params *params;
+ struct kmem_cache *cachep;
+
+ params = container_of(work, struct mem_cgroup_cache_params,
+ cache_shrinker);
+ cachep = container_of(params, struct kmem_cache, memcg_params);
+
+ kmem_cache_shrink(cachep);
+}
+
static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
struct kmem_cache *cachep)
{
struct kmem_cache *new_cachep;
int idx;
+ char *name;
BUG_ON(!mem_cgroup_kmem_enabled(memcg));
@@ -581,10 +594,21 @@ static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
goto out;
}
+ /*
+ * Because the cache is expected to duplicate the string,
+ * we must make sure it has opportunity to copy its full
+ * name. Only now we can remove the dead part from it
+ */
+ name = (char *)new_cachep->name;
+ if (name)
+ name[strlen(name) - 4] = '\0';
+
mem_cgroup_get(memcg);
memcg->slabs[idx] = new_cachep;
new_cachep->memcg_params.memcg = memcg;
atomic_set(&new_cachep->memcg_params.refcnt, 1);
+ INIT_WORK(&new_cachep->memcg_params.cache_shrinker,
+ cache_shrinker_work_func);
out:
mutex_unlock(&memcg_cache_mutex);
return new_cachep;
@@ -607,6 +631,21 @@ static void kmem_cache_destroy_work_func(struct work_struct *w)
struct mem_cgroup_cache_params *p, *tmp;
unsigned long flags;
LIST_HEAD(del_unlocked);
+ LIST_HEAD(shrinkers);
+
+ spin_lock_irqsave(&cache_queue_lock, flags);
+ list_for_each_entry_safe(p, tmp, &destroyed_caches, destroyed_list) {
+ cachep = container_of(p, struct kmem_cache, memcg_params);
+ if (atomic_read(&cachep->memcg_params.refcnt) != 0)
+ list_move(&cachep->memcg_params.destroyed_list, &shrinkers);
+ }
+ spin_unlock_irqrestore(&cache_queue_lock, flags);
+
+ list_for_each_entry_safe(p, tmp, &shrinkers, destroyed_list) {
+ cachep = container_of(p, struct kmem_cache, memcg_params);
+ list_del(&cachep->memcg_params.destroyed_list);
+ kmem_cache_shrink(cachep);
+ }
spin_lock_irqsave(&cache_queue_lock, flags);
list_for_each_entry_safe(p, tmp, &destroyed_caches, destroyed_list) {
@@ -682,12 +721,16 @@ static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
spin_lock_irqsave(&cache_queue_lock, flags);
for (i = 0; i < MAX_KMEM_CACHE_TYPES; i++) {
+ char *name;
cachep = memcg->slabs[i];
if (!cachep)
continue;
- if (atomic_dec_and_test(&cachep->memcg_params.refcnt))
- __mem_cgroup_destroy_cache(cachep);
+ atomic_dec(&cachep->memcg_params.refcnt);
+ cachep->memcg_params.dead = true;
+ name = (char *)cachep->name;
+ name[strlen(name)] = 'd';
+ __mem_cgroup_destroy_cache(cachep);
}
spin_unlock_irqrestore(&cache_queue_lock, flags);
diff --git a/mm/slub.c b/mm/slub.c
index eb0ff97..f5fc10c 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2658,6 +2658,7 @@ redo:
} else
__slab_free(s, page, x, addr);
+ kmem_cache_verify_dead(s);
}
void kmem_cache_free(struct kmem_cache *s, void *x)
--
1.7.7.6
|
|
|
|
| [PATCH v3 19/28] slab: per-memcg accounting of slab caches [message #46526 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
This patch charges allocation of a slab object to a particular
memcg.
The cache is selected with mem_cgroup_get_kmem_cache(),
which is the biggest overhead we pay here, because
it happens at all allocations. However, other than forcing
a function call, this function is not very expensive, and
try to return as soon as we realize we are not a memcg cache.
The charge/uncharge functions are heavier, but are only called
for new page allocations.
Code is heavily inspired by Suleiman's, with adaptations to
the patchset and minor simplifications by me.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
---
include/linux/slab_def.h | 62 +++++++++++++++++++++++++++++
mm/slab.c | 98 +++++++++++++++++++++++++++++++++++++++++----
2 files changed, 151 insertions(+), 9 deletions(-)
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index 7c0cdd6..ea9054a 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -225,4 +225,66 @@ found:
#endif /* CONFIG_NUMA */
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+
+void kmem_cache_drop_ref(struct kmem_cache *cachep);
+
+static inline void
+kmem_cache_get_ref(struct kmem_cache *cachep)
+{
+ if (cachep->memcg_params.id == -1 &&
+ unlikely(!atomic_add_unless(&cachep->memcg_params.refcnt, 1, 0)))
+ BUG();
+}
+
+static inline void
+mem_cgroup_put_kmem_cache(struct kmem_cache *cachep)
+{
+ rcu_read_unlock();
+}
+
+static inline void
+mem_cgroup_kmem_cache_prepare_sleep(struct kmem_cache *cachep)
+{
+ /*
+ * Make sure the cache doesn't get freed while we have interrupts
+ * enabled.
+ */
+ kmem_cache_get_ref(cachep);
+}
+
+static inline void
+mem_cgroup_kmem_cache_finish_sleep(struct kmem_cache *cachep)
+{
+ kmem_cache_drop_ref(cachep);
+}
+
+#else /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+
+static inline void
+kmem_cache_get_ref(struct kmem_cache *cachep)
+{
+}
+
+static inline void
+kmem_cache_drop_ref(struct kmem_cache *cachep)
+{
+}
+
+static inline void
+mem_cgroup_put_kmem_cache(struct kmem_cache *cachep)
+{
+}
+
+static inline void
+mem_cgroup_kmem_cache_prepare_sleep(struct kmem_cache *cachep)
+{
+}
+
+static inline void
+mem_cgroup_kmem_cache_finish_sleep(struct kmem_cache *cachep)
+{
+}
+#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+
#endif /* _LINUX_SLAB_DEF_H */
diff --git a/mm/slab.c b/mm/slab.c
index e2227de..16ad229 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1845,20 +1845,28 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
flags |= __GFP_RECLAIMABLE;
+ nr_pages = (1 << cachep->gfporder);
+ if (!mem_cgroup_charge_slab(cachep, flags, nr_pages * PAGE_SIZE))
+ return NULL;
+
page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder);
if (!page) {
if (!(flags & __GFP_NOWARN) && printk_ratelimit())
slab_out_of_memory(cachep, flags, nodeid);
+
+ mem_cgroup_uncharge_slab(cachep, nr_pages * PAGE_SIZE);
return NULL;
}
- nr_pages = (1 << cachep->gfporder);
if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
add_zone_page_state(page_zone(page),
NR_SLAB_RECLAIMABLE, nr_pages);
else
add_zone_page_state(page_zone(page),
NR_SLAB_UNRECLAIMABLE, nr_pages);
+
+ kmem_cache_get_ref(cachep);
+
for (i = 0; i < nr_pages; i++)
__SetPageSlab(page + i);
@@ -1874,6 +1882,14 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
return page_address(page);
}
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+void kmem_cache_drop_ref(struct kmem_cache *cachep)
+{
+ if (cachep->memcg_params.id == -1)
+ atomic_dec(&cachep->memcg_params.refcnt);
+}
+#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+
/*
* Interface to system's page release.
*/
@@ -1891,6 +1907,8 @@ static void kmem_freepages(struct kmem_cache *cachep, void *addr)
else
sub_zone_page_state(page_zone(page),
NR_SLAB_UNRECLAIMABLE, nr_freed);
+ mem_cgroup_uncharge_slab(cachep, i * PAGE_SIZE);
+ kmem_cache_drop_ref(cachep);
while (i--) {
BUG_ON(!PageSlab(page));
__ClearPageSlab(page);
@@ -2855,7 +2873,6 @@ void kmem_cache_destroy(struct kmem_cache *cachep)
if (cachep->memcg_params.id == -1)
kfree(cachep->name);
#endif
-
__kmem_cache_destroy(cachep);
mutex_unlock(&cache_chain_mutex);
put_online_cpus();
@@ -3061,8 +3078,10 @@ static int cache_grow(struct kmem_cache *cachep,
offset *= cachep->colour_off;
- if (local_flags & __GFP_WAIT)
+ if (local_flags & __GFP_WAIT) {
local_irq_enable();
+ mem_cgroup_kmem_cache_prepare_sleep(cachep);
+ }
/*
* The test for missing atomic flag is performed here, rather than
@@ -3091,8 +3110,10 @@ static int cache_grow(struct kmem_cache *cachep,
cache_init_objs(cachep, slabp);
- if (local_flags & __GFP_WAIT)
+ if (local_flags & __GFP_WAIT) {
local_irq_disable();
+ mem_cgroup_kmem_cache_finish_sleep(cachep);
+ }
check_irq_off();
spin_lock(&l3->list_lock);
@@ -3105,8 +3126,10 @@ static int cache_grow(struct kmem_cache *cachep,
opps1:
kmem_freepages(cachep, objp);
failed:
- if (local_flags & __GFP_WAIT)
+ if (local_flags & __GFP_WAIT) {
local_irq_disable();
+ mem_cgroup_kmem_cache_finish_sleep(cachep);
+ }
return 0;
}
@@ -3867,11 +3890,15 @@ static inline void __cache_free(struct kmem_cache *cachep, void *objp,
*/
void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
{
- void *ret = __cache_alloc(cachep, flags, __builtin_return_address(0));
+ void *ret;
+
+ rcu_read_lock();
+ cachep = mem_cgroup_get_kmem_cache(cachep, flags);
+ rcu_read_unlock();
+ ret = __cache_alloc(cachep, flags, __builtin_return_address(0));
trace_kmem_cache_alloc(_RET_IP_, ret,
obj_size(cachep), cachep->buffer_size, flags);
-
return ret;
}
EXPORT_SYMBOL(kmem_cache_alloc);
@@ -3882,6 +3909,10 @@ kmem_cache_alloc_trace(size_t size, struct kmem_cache *cachep, gfp_t flags)
{
void *ret;
+ rcu_read_lock();
+ cachep = mem_cgroup_get_kmem_cache(cachep, flags);
+ rcu_read_unlock();
+
ret = __cache_alloc(cachep, flags, __builtin_return_address(0));
trace_kmalloc(_RET_IP_, ret,
@@ -3894,13 +3925,17 @@ EXPORT_SYMBOL(kmem_cache_alloc_trace);
#ifdef CONFIG_NUMA
void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
{
- void *ret = __cache_alloc_node(cachep, flags, nodeid,
+ void *ret;
+
+ rcu_read_lock();
+ cachep = mem_cgroup_get_kmem_cache(cachep, flags);
+ rcu_read_unlock();
+ ret = __cache_alloc_node(cachep, flags, nodeid,
__builtin_return_address(0));
trace_kmem_cache_alloc_node(_RET_IP_, ret,
obj_size(cachep), cachep->buffer_size,
flags, nodeid);
-
return ret;
}
EXPORT_SYMBOL(kmem_cache_alloc_node);
@@ -3913,6 +3948,9 @@ void *kmem_cache_alloc_node_trace(size_t size,
{
void *ret;
+ rcu_read_lock();
+ cachep = mem_cgroup_get_kmem_cache(cachep, flags);
+ rcu_read_unlock();
ret = __cache_alloc_node(cachep, flags, nodeid,
__builtin_return_address(0));
trace_kmalloc_node(_RET_IP_, ret,
@@ -4021,9 +4059,33 @@ void kmem_cache_free(struct kmem_cache *cachep, void *objp)
local_irq_save(flags);
debug_check_no_locks_freed(objp, obj_size(cachep));
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ {
+ struct kmem_cache *actual_cachep;
+
+ actual_cachep = virt_to_cache(objp);
+ if (actual_cachep != cachep) {
+ VM_BUG_ON(actual_cachep->memcg_params.id != -1);
+ cachep = actual_cachep;
+ }
+ /*
+ * Grab a reference so that the cache is guaranteed to stay
+ * around.
+ * If we are freeing the last object of a dead memcg cache,
+ * the kmem_cache_drop_ref() at the end of this function
+ * will end up freeing the cache.
+ */
+ kmem_cache_get_ref(cachep);
+ }
+#endif
+
if (!(cachep->flags & SLAB_DEBUG_OBJECTS))
debug_check_no_obj_freed(objp, obj_size(cachep));
__cache_free(cachep, objp, __builtin_return_address(0));
+
+ kmem_cache_drop_ref(cachep);
+
local_irq_restore(flags);
trace_kmem_cache_free(_RET_IP_, objp);
@@ -4051,9 +4113,19 @@ void kfree(const void *objp)
local_irq_save(flags);
kfree_debugcheck(objp);
c = virt_to_cache(objp);
+
+ /*
+ * Grab a reference so that the cache is guaranteed to stay around.
+ * If we are freeing the last object of a dead memcg cache, the
+ * kmem_cache_drop_ref() at the end of this function will end up
+ * freeing the cache.
+ */
+ kmem_cache_get_ref(c);
+
debug_check_no_locks_freed(objp, obj_size(c));
debug_check_no_obj_freed(objp, obj_size(c));
__cache_free(c, (void *)objp, __builtin_return_address(0));
+ kmem_cache_drop_ref(c);
local_irq_restore(flags);
}
EXPORT_SYMBOL(kfree);
@@ -4322,6 +4394,13 @@ static void cache_reap(struct work_struct *w)
list_for_each_entry(searchp, &cache_chain, next) {
check_irq_on();
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ /* For memcg caches, make sure we only reap the active ones. */
+ if (searchp->memcg_params.id == -1 &&
+ !atomic_add_unless(&searchp->memcg_params.refcnt, 1, 0))
+ continue;
+#endif
+
/*
* We only take the l3 lock if absolutely necessary and we
* have established with reasonable certainty that
@@ -4354,6 +4433,7 @@ static void cache_reap(struct work_struct *w)
STATS_ADD_REAPED(searchp, freed);
}
next:
+ kmem_cache_drop_ref(searchp);
cond_resched();
}
check_irq_on();
--
1.7.7.6
...
|
|
|
|
| [PATCH v3 21/28] memcg: destroy memcg caches [message #46527 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
This patch implements destruction of memcg caches. Right now,
only caches where our reference counter is the last remaining are
deleted. If there are any other reference counters around, we just
leave the caches lying around until they go away.
When that happen, a destruction function is called from the cache
code. Caches are only destroyed in process context, so we queue them
up for later processing in the general case.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Suleiman Souhlal <suleiman@google.com>
---
include/linux/memcontrol.h | 2 +
include/linux/slab.h | 1 +
mm/memcontrol.c | 91 +++++++++++++++++++++++++++++++++++++++++++-
mm/slab.c | 5 +-
mm/slub.c | 7 ++-
5 files changed, 101 insertions(+), 5 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index bad8ebd..df049e1 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -463,6 +463,8 @@ __mem_cgroup_get_kmem_cache(struct kmem_cache *cachep, gfp_t gfp);
extern struct static_key mem_cgroup_kmem_enabled_key;
#define mem_cgroup_kmem_on static_key_false(&mem_cgroup_kmem_enabled_key)
+
+void mem_cgroup_destroy_cache(struct kmem_cache *cachep);
#else
static inline void mem_cgroup_register_cache(struct mem_cgroup *memcg,
struct kmem_cache *s)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 724c143..c81a5d3 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -167,6 +167,7 @@ struct mem_cgroup_cache_params {
#ifdef CONFIG_DEBUG_VM
struct kmem_cache *parent;
#endif
+ struct list_head destroyed_list; /* Used when deleting memcg cache */
};
#endif
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f2f1525..e2ba527 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -476,6 +476,11 @@ static void disarm_static_keys(struct mem_cgroup *memcg)
{
if (memcg->kmem_accounted)
static_key_slow_dec(&mem_cgroup_kmem_enabled_key);
+ /*
+ * This check can't live in kmem destruction function,
+ * since the charges will outlive the cgroup
+ */
+ BUG_ON(res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0);
}
#ifdef CONFIG_INET
@@ -540,6 +545,8 @@ void mem_cgroup_register_cache(struct mem_cgroup *memcg,
if (!memcg)
id = ida_simple_get(&cache_types, 0, MAX_KMEM_CACHE_TYPES,
GFP_KERNEL);
+ else
+ INIT_LIST_HEAD(&cachep->memcg_params.destroyed_list);
cachep->memcg_params.id = id;
}
@@ -592,6 +599,53 @@ struct create_work {
/* Use a single spinlock for destruction and creation, not a frequent op */
static DEFINE_SPINLOCK(cache_queue_lock);
static LIST_HEAD(create_queue);
+static LIST_HEAD(destroyed_caches);
+
+static void kmem_cache_destroy_work_func(struct work_struct *w)
+{
+ struct kmem_cache *cachep;
+ struct mem_cgroup_cache_params *p, *tmp;
+ unsigned long flags;
+ LIST_HEAD(del_unlocked);
+
+ spin_lock_irqsave(&cache_queue_lock, flags);
+ list_for_each_entry_safe(p, tmp, &destroyed_caches, destroyed_list) {
+ cachep = container_of(p, struct kmem_cache, memcg_params);
+ list_move(&cachep->memcg_params.destroyed_list, &del_unlocked);
+ }
+ spin_unlock_irqrestore(&cache_queue_lock, flags);
+
+ list_for_each_entry_safe(p, tmp, &del_unlocked, destroyed_list) {
+ cachep = container_of(p, struct kmem_cache, memcg_params);
+ list_del(&cachep->memcg_params.destroyed_list);
+ if (!atomic_read(&cachep->memcg_params.refcnt)) {
+ mem_cgroup_put(cachep->memcg_params.memcg);
+ kmem_cache_destroy(cachep);
+ }
+ }
+}
+static DECLARE_WORK(kmem_cache_destroy_work, kmem_cache_destroy_work_func);
+
+static void __mem_cgroup_destroy_cache(struct kmem_cache *cachep)
+{
+ BUG_ON(cachep->memcg_params.id != -1);
+ list_add(&cachep->memcg_params.destroyed_list, &destroyed_caches);
+}
+
+void mem_cgroup_destroy_cache(struct kmem_cache *cachep)
+{
+ unsigned long flags;
+
+ /*
+ * We have to defer the actual destroying to a workqueue, because
+ * we might currently be in a context that cannot sleep.
+ */
+ spin_lock_irqsave(&cache_queue_lock, flags);
+ __mem_cgroup_destroy_cache(cachep);
+ spin_unlock_irqrestore(&cache_queue_lock, flags);
+
+ schedule_work(&kmem_cache_destroy_work);
+}
/*
* Flush the queue of kmem_caches to create, because we're creating a cgroup.
@@ -613,6 +667,33 @@ void mem_cgroup_flush_cache_create_queue(void)
spin_unlock_irqrestore(&cache_queue_lock, flags);
}
+static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
+{
+ struct kmem_cache *cachep;
+ unsigned long flags;
+ int i;
+
+ /*
+ * pre_destroy() gets called with no tasks in the cgroup.
+ * this means that after flushing the create queue, no more caches
+ * will appear
+ */
+ mem_cgroup_flush_cache_create_queue();
+
+ spin_lock_irqsave(&cache_queue_lock, flags);
+ for (i = 0; i < MAX_KMEM_CACHE_TYPES; i++) {
+ cachep = memcg->slabs[i];
+ if (!cachep)
+ continue;
+
+ if (atomic_dec_and_test(&cachep->memcg_params.refcnt))
+ __mem_cgroup_destroy_cache(cachep);
+ }
+ spin_unlock_irqrestore(&cache_queue_lock, flags);
+
+ schedule_work(&kmem_cache_destroy_work);
+}
+
static void memcg_create_cache_work_func(struct work_struct *w)
{
struct create_work *cw, *tmp;
@@ -857,6 +938,10 @@ static void memcg_slab_init(struct mem_cgroup *memcg)
static inline void disarm_static_keys(struct mem_cgroup *memcg)
{
}
+
+static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
+{
+}
#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
static void drain_all_stock_async(struct mem_cgroup *memcg);
@@ -4136,6 +4221,7 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg, bool free_all)
int node, zid, shrink;
int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
struct cgroup *cgrp = memcg->css.cgroup;
+ u64 usage;
css_get(&memcg->css);
@@ -4175,8 +4261,10 @@ move_account:
if (ret == -ENOMEM)
goto try_to_free;
cond_resched();
+ usage = res_counter_read_u64(&memcg->res, RES_USAGE) -
+ res_counter_read_u64(&memcg->kmem, RES_USAGE);
/* "ret" should also be checked to ensure all lists are empty. */
- } while (res_counter_read_u64(&memcg->res, RES_USAGE) > 0 || ret);
+ } while (usage > 0 || ret);
out:
css_put(&memcg->css);
return ret;
@@ -5523,6 +5611,7 @@ static int mem_cgroup_pre_destroy(struct cgroup *cont)
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+ mem_cgroup_destroy_all_caches(memcg);
return mem_cgroup_force_empty(memcg, false);
}
diff --git a/mm/slab.c b/mm/slab.c
index 16ad229..59f1027 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1885,8 +1885,9 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
void kmem_cache_drop_ref(struct kmem_cache *cachep)
{
- if (cachep->memcg_params.id == -1)
- atomic_dec(&cachep->memcg_params.refcnt);
+ if (cachep->memcg_params.id == -1 &&
+ unlikely(atomic_dec_and_test(&cachep->memcg_params.refcnt)))
+ mem_cgroup_destroy_cache(cachep);
}
#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
diff --git a/mm/slub.c b/mm/slub.c
index 730e69f..eb0ff97 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1296,8 +1296,11 @@ static void kmem_cache_inc_ref(struct kmem_cache *s)
}
static void kmem_cache_drop_ref(struct kmem_cache *s)
{
- if (s->memcg_params.memcg)
- atomic_dec(&s->memcg_params.refcnt);
+ if (!s->memcg_params.memcg)
+ return;
+
+ if (unlikely(atomic_dec_and_test(&s->memcg_params.refcnt)))
+ mem_cgroup_destroy_cache(s);
}
#else
static inline void kmem_cache_inc_ref(struct kmem_cache *s)
--
1.7.7.6
|
|
|
|
| [PATCH v3 25/28] slub: create slabinfo file for memcg [message #46528 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
This patch implements mem_cgroup_slabinfo() for the slub.
With that, we can also probe the used caches for it.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Suleiman Souhlal <suleiman@google.com>
---
mm/slub.c | 27 +++++++++++++++++++++++++++
1 files changed, 27 insertions(+), 0 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index c8a8cab..4c29e5f 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4113,6 +4113,33 @@ struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
int mem_cgroup_slabinfo(struct mem_cgroup *memcg, struct seq_file *m)
{
+ struct kmem_cache *s;
+ int node;
+ unsigned long nr_objs = 0;
+ unsigned long nr_free = 0;
+
+ seq_printf(m, "# name <active_objs> <num_objs> <objsize>\n");
+
+ down_read(&slub_lock);
+ list_for_each_entry(s, &slab_caches, list) {
+ if (s->memcg_params.memcg != memcg)
+ continue;
+
+ for_each_online_node(node) {
+ struct kmem_cache_node *n = get_node(s, node);
+
+ if (!n)
+ continue;
+
+ nr_objs += atomic_long_read(&n->total_objects);
+ nr_free += count_partial(n, count_free);
+ }
+
+ seq_printf(m, "%-17s %6lu %6lu %6u\n", s->name,
+ nr_objs - nr_free, nr_objs, s->size);
+ }
+ up_read(&slub_lock);
+
return 0;
}
#endif
--
1.7.7.6
|
|
|
|
| [PATCH v3 16/28] memcg: kmem controller charge/uncharge infrastructure [message #46529 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
With all the dependencies already in place, this patch introduces
the charge/uncharge functions for the slab cache accounting in memcg.
Before we can charge a cache, we need to select the right cache.
This is done by using the function __mem_cgroup_get_kmem_cache().
If we should use the root kmem cache, this function tries to detect
that and return as early as possible.
The charge and uncharge functions comes in two flavours:
* __mem_cgroup_(un)charge_slab(), that assumes the allocation is
a slab page, and
* __mem_cgroup_(un)charge_kmem(), that does not. This later exists
because the slub allocator draws the larger kmalloc allocations
from the page allocator.
In memcontrol.h those functions are wrapped in inline acessors.
The idea is to later on, patch those with jump labels, so we don't
incur any overhead when no mem cgroups are being used.
Because the slub allocator tends to inline the allocations whenever
it can, those functions need to be exported so modules can make use
of it properly.
This code is inspired by the code written by Suleiman Souhlal,
but heavily changed.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
---
include/linux/memcontrol.h | 80 +++++++++
init/Kconfig | 2 +-
mm/memcontrol.c | 386 +++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 466 insertions(+), 2 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index f93021a..fbc5ba1 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -21,6 +21,7 @@
#define _LINUX_MEMCONTROL_H
#include <linux/cgroup.h>
#include <linux/vm_event_item.h>
+#include <linux/hardirq.h>
struct mem_cgroup;
struct page_cgroup;
@@ -447,6 +448,19 @@ void mem_cgroup_register_cache(struct mem_cgroup *memcg,
void mem_cgroup_release_cache(struct kmem_cache *cachep);
extern char *mem_cgroup_cache_name(struct mem_cgroup *memcg,
struct kmem_cache *cachep);
+
+void mem_cgroup_flush_cache_create_queue(void);
+bool __mem_cgroup_charge_slab(struct kmem_cache *cachep, gfp_t gfp,
+ size_t size);
+void __mem_cgroup_uncharge_slab(struct kmem_cache *cachep, size_t size);
+
+bool __mem_cgroup_new_kmem_page(struct page *page, gfp_t gfp);
+void __mem_cgroup_free_kmem_page(struct page *page);
+
+struct kmem_cache *
+__mem_cgroup_get_kmem_cache(struct kmem_cache *cachep, gfp_t gfp);
+
+#define mem_cgroup_kmem_on 1
#else
static inline void mem_cgroup_register_cache(struct mem_cgroup *memcg,
struct kmem_cache *s)
@@ -463,6 +477,72 @@ static inline void sock_update_memcg(struct sock *sk)
static inline void sock_release_memcg(struct sock *sk)
{
}
+
+static inline void
+mem_cgroup_flush_cache_create_queue(void)
+{
+}
+
+static inline void mem_cgroup_destroy_cache(struct kmem_cache *cachep)
+{
+}
+
+#define mem_cgroup_kmem_on 0
+#define __mem_cgroup_get_kmem_cache(a, b) a
+#define __mem_cgroup_charge_slab(a, b, c) false
+#define __mem_cgroup_new_kmem_page(a, gfp) false
+#define __mem_cgroup_uncharge_slab(a, b)
+#define __mem_cgroup_free_kmem_page(b)
#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+static __always_inline struct kmem_cache *
+mem_cgroup_get_kmem_cache(struct kmem_cache *cachep, gfp_t gfp)
+{
+ if (!mem_cgroup_kmem_on)
+ return cachep;
+ if (!current->mm)
+ return cachep;
+ if (in_interrupt())
+ return cachep;
+ if (gfp & __GFP_NOFAIL)
+ return cachep;
+
+ return __mem_cgroup_get_kmem_cache(cachep, gfp);
+}
+
+static __always_inline bool
+mem_cgroup_charge_slab(struct kmem_cache *cachep, gfp_t gfp, size_t size)
+{
+ if (mem_cgroup_kmem_on)
+ return __mem_cgroup_charge_slab(cachep, gfp, size);
+ return true;
+}
+
+static __always_inline void
+mem_cgroup_uncharge_slab(struct kmem_cache *cachep, size_t size)
+{
+ if (mem_cgroup_kmem_on)
+ __mem_cgroup_uncharge_slab(cachep, size);
+}
+
+static __always_inline
+bool mem_cgroup_new_kmem_page(struct page *page, gfp_t gfp)
+{
+ if (!mem_cgroup_kmem_on)
+ return true;
+ if (!current->mm)
+ return true;
+ if (in_interrupt())
+ return true;
+ if (gfp & __GFP_NOFAIL)
+ return true;
+ return __mem_cgroup_new_kmem_page(page, gfp);
+}
+
+static __always_inline
+void mem_cgroup_free_kmem_page(struct page *page)
+{
+ if (mem_cgroup_kmem_on)
+ __mem_cgroup_free_kmem_page(page);
+}
#endif /* _LINUX_MEMCONTROL_H */
diff --git a/init/Kconfig b/init/Kconfig
index 72f33fa..071b7e3 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -696,7 +696,7 @@ config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
then swapaccount=0 does the trick).
config CGROUP_MEM_RES_CTLR_KMEM
bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
- depends on CGROUP_MEM_RES_CTLR && EXPERIMENTAL
+ depends on CGROUP_MEM_RES_CTLR && EXPERIMENTAL && !SLOB
default n
help
The Kernel Memory extension for Memory Resource Controller can limit
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4689034..44589fb 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -10,6 +10,10 @@
* Copyright (C) 2009 Nokia Corporation
* Author: Kirill A. Shutemov
*
+ * Kernel Memory Controller
+ * Copyright (C) 2012 Parallels Inc. and Google Inc.
+ * Authors: Glauber Costa and Suleiman Souhlal
+ *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
@@ -321,6 +325,11 @@ struct mem_cgroup {
#ifdef CONFIG_INET
struct tcp_memcontrol tcp_mem;
#endif
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ /* Slab accounting */
+ struct kmem_cache *slabs[MAX_KMEM_CACHE_TYPES];
+#endif
};
int memcg_css_id(struct mem_cgroup *memcg)
@@ -414,6 +423,9 @@ static void mem_cgroup_put(struct mem_cgroup *memcg);
#include <net/ip.h>
static bool mem_cgroup_is_root(struct mem_cgroup *memcg);
+static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, s64 delta);
+static void memcg_uncharge_kmem(struct mem_cgroup *memcg, s64 delta);
+
void sock_update_memcg(struct sock *sk)
{
if (mem_cgroup_sockets_enabled) {
@@ -484,7 +496,14 @@ char *mem_cgroup_cache_name(struct mem_cgroup *memcg, struct kmem_cache *cachep)
return name;
}
+static inline bool mem_cgroup_kmem_enabled(struct mem_cgroup *memcg)
+{
+ return !mem_cgroup_disabled() && memcg &&
+ !mem_cgroup_is_root(memcg) && memcg->kmem_accounted;
+}
+
struct ida cache_types;
+static DEFINE_MUTEX(memcg_cache_mutex);
void mem_cgroup_register_cache(struct mem_cgroup *memcg,
struct kmem_cache *cachep)
@@ -501,9 +520,304 @@ void mem_cgroup_register_cache(struct mem_cgroup *memcg,
void mem_cgroup_release_cache(struct kmem_cache *cachep)
{
+ mem_cgroup_flush_cache_create_queue();
if (cachep->memcg_params.id != -1)
ida_simple_remove(&cache_types, cachep->memcg_params.id);
}
+
+static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
+ struct kmem_cache *cachep)
+{
+ struct kmem_cache *new_cachep;
+ int idx;
+
+ BUG_ON(!mem_cgroup_kmem_enabled(memcg));
+
+ idx = cachep->memcg_params.id;
+
+ mutex_lock(&memcg_cache_mutex);
+ new_cachep = memcg->slabs[idx];
+ if (new_cachep)
+ goto out;
+
+ new_cachep = kmem_cache_dup(memcg, cachep);
+
+ if (new_cachep == NULL) {
+ new_cachep = cachep;
+ goto out;
+ }
+
+ mem_cgroup_get(memcg);
+ memcg->slabs[idx] = new_cachep;
+ new_cachep->memcg_params.memcg = memcg;
+ atomic_set(&new_cachep->memcg_params.refcnt, 1);
+out:
+ mutex_unlock(&memcg_cache_mutex);
+ return new_cachep;
+}
+
+struct create_work {
+ struct mem_cgroup *memcg;
+ struct kmem_cache *cachep;
+ struct list_head list;
+};
+
+/* Use a single spinlock for destruction and creation, not a frequent op */
+static DEFINE_SPINLOCK(cache_queue_lock);
+static LIST_HEAD(create_queue);
+
+/*
+ * Flush the queue of kmem_caches to create, because we're creating a cgroup.
+ *
+ * We might end up flushing other cgroups' creation requests as well, but
+ * they will just get queued again next time someone tries to make a slab
+ * allocation for them.
+ */
+void mem_cgroup_flush_cache_create_queue(void)
+{
+ struct create_work *cw, *tmp;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cache_queue_lock, flags);
+ list_for_each_entry_safe(cw, tmp, &create_queue, list) {
+ list_del(&cw->list);
+ kfree(cw);
+ }
+ spin_unlock_irqrestore(&cache_queue_lock, flags);
+}
+
+static void memcg_create_cache_work_func(struct work_struct *w)
+{
+ struct create_work *cw, *tmp;
+ unsigned long flags;
+ LIST_HEAD(create_unlocked);
+
+ spin_lock_irqsave(&cache_queue_lock, flags);
+ list_for_each_entry_safe(cw, tmp, &create_queue, list)
+ list_move(&cw->list, &create_unlocked);
+ spin_unlock_irqrestore(&cache_queue_lock, flags);
+
+ list_for_each_entry_safe(cw, tmp, &create_unlocked, list) {
+ list_del(&cw->list);
+ memcg_create_kmem_cache(cw->memcg, cw->cachep);
+ /* Drop the reference gotten when we enqueued. */
+ css_put(&cw->memcg->css);
+ kfree(cw);
+ }
+}
+
+static DECLARE_WORK(memcg_create_cache_work, memcg_create_cache_work_func);
+
+/*
+ * Enqueue the creation of a per-memcg kmem_cache.
+ * Called with rcu_read_lock.
+ */
+static void memcg_create_cache_enqueue(struct mem_cgroup *memcg,
+ struct kmem_cache *cachep)
+{
+ struct create_work *cw;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cache_queue_lock, flags);
+ list_for_each_entry(cw, &create_queue, list) {
+ if (cw->memcg == memcg && cw->cachep == cachep) {
+ spi
...
|
|
|
|
| [PATCH v3 24/28] memcg: Per-memcg memory.kmem.slabinfo file. [message #46530 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
From: Suleiman Souhlal <ssouhlal@FreeBSD.org>
This file shows all the kmem_caches used by a memcg.
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
---
include/linux/slab.h | 1 +
mm/memcontrol.c | 17 ++++++++++
mm/slab.c | 87 ++++++++++++++++++++++++++++++++++++-------------
mm/slub.c | 5 +++
4 files changed, 87 insertions(+), 23 deletions(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 714aeab..f2f51d8 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -333,6 +333,7 @@ extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
#define MAX_KMEM_CACHE_TYPES 400
extern struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
struct kmem_cache *cachep);
+extern int mem_cgroup_slabinfo(struct mem_cgroup *mem, struct seq_file *m);
#else
#define MAX_KMEM_CACHE_TYPES 0
#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 08f3c3e..3e99c69 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5229,6 +5229,19 @@ static int mem_control_numa_stat_open(struct inode *unused, struct file *file)
#endif /* CONFIG_NUMA */
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+static int mem_cgroup_slabinfo_show(struct cgroup *cgroup, struct cftype *ctf,
+ struct seq_file *m)
+{
+ struct mem_cgroup *mem;
+
+ mem = mem_cgroup_from_cont(cgroup);
+
+ if (mem == root_mem_cgroup)
+ mem = NULL;
+
+ return mem_cgroup_slabinfo(mem, m);
+}
+
static struct cftype kmem_cgroup_files[] = {
{
.name = "kmem.limit_in_bytes",
@@ -5253,6 +5266,10 @@ static struct cftype kmem_cgroup_files[] = {
.trigger = mem_cgroup_reset,
.read = mem_cgroup_read,
},
+ {
+ .name = "kmem.slabinfo",
+ .read_seq_string = mem_cgroup_slabinfo_show,
+ },
{},
};
diff --git a/mm/slab.c b/mm/slab.c
index cb409ae..2f9cf92 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -4550,21 +4550,26 @@ static void s_stop(struct seq_file *m, void *p)
mutex_unlock(&cache_chain_mutex);
}
-static int s_show(struct seq_file *m, void *p)
-{
- struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
- struct slab *slabp;
+struct slab_counts {
unsigned long active_objs;
+ unsigned long active_slabs;
+ unsigned long num_slabs;
+ unsigned long free_objects;
+ unsigned long shared_avail;
unsigned long num_objs;
- unsigned long active_slabs = 0;
- unsigned long num_slabs, free_objects = 0, shared_avail = 0;
- const char *name;
- char *error = NULL;
- int node;
+};
+
+static char *
+get_slab_counts(struct kmem_cache *cachep, struct slab_counts *c)
+{
struct kmem_list3 *l3;
+ struct slab *slabp;
+ char *error;
+ int node;
+
+ error = NULL;
+ memset(c, 0, sizeof(struct slab_counts));
- active_objs = 0;
- num_slabs = 0;
for_each_online_node(node) {
l3 = cachep->nodelists[node];
if (!l3)
@@ -4576,31 +4581,43 @@ static int s_show(struct seq_file *m, void *p)
list_for_each_entry(slabp, &l3->slabs_full, list) {
if (slabp->inuse != cachep->num && !error)
error = "slabs_full accounting error";
- active_objs += cachep->num;
- active_slabs++;
+ c->active_objs += cachep->num;
+ c->active_slabs++;
}
list_for_each_entry(slabp, &l3->slabs_partial, list) {
if (slabp->inuse == cachep->num && !error)
error = "slabs_partial inuse accounting error";
if (!slabp->inuse && !error)
error = "slabs_partial/inuse accounting error";
- active_objs += slabp->inuse;
- active_slabs++;
+ c->active_objs += slabp->inuse;
+ c->active_slabs++;
}
list_for_each_entry(slabp, &l3->slabs_free, list) {
if (slabp->inuse && !error)
error = "slabs_free/inuse accounting error";
- num_slabs++;
+ c->num_slabs++;
}
- free_objects += l3->free_objects;
+ c->free_objects += l3->free_objects;
if (l3->shared)
- shared_avail += l3->shared->avail;
+ c->shared_avail += l3->shared->avail;
spin_unlock_irq(&l3->list_lock);
}
- num_slabs += active_slabs;
- num_objs = num_slabs * cachep->num;
- if (num_objs - active_objs != free_objects && !error)
+ c->num_slabs += c->active_slabs;
+ c->num_objs = c->num_slabs * cachep->num;
+
+ return error;
+}
+
+static int s_show(struct seq_file *m, void *p)
+{
+ struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
+ struct slab_counts c;
+ const char *name;
+ char *error;
+
+ error = get_slab_counts(cachep, &c);
+ if (c.num_objs - c.active_objs != c.free_objects && !error)
error = "free_objects accounting error";
name = cachep->name;
@@ -4608,12 +4625,12 @@ static int s_show(struct seq_file *m, void *p)
printk(KERN_ERR "slab: cache %s error: %s\n", name, error);
seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
- name, active_objs, num_objs, cachep->buffer_size,
+ name, c.active_objs, c.num_objs, cachep->buffer_size,
cachep->num, (1 << cachep->gfporder));
seq_printf(m, " : tunables %4u %4u %4u",
cachep->limit, cachep->batchcount, cachep->shared);
seq_printf(m, " : slabdata %6lu %6lu %6lu",
- active_slabs, num_slabs, shared_avail);
+ c.active_slabs, c.num_slabs, c.shared_avail);
#if STATS
{ /* list3 stats */
unsigned long high = cachep->high_mark;
@@ -4647,6 +4664,30 @@ static int s_show(struct seq_file *m, void *p)
return 0;
}
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+int mem_cgroup_slabinfo(struct mem_cgroup *memcg, struct seq_file *m)
+{
+ struct kmem_cache *cachep;
+ struct slab_counts c;
+
+ seq_printf(m, "# name <active_objs> <num_objs> <objsize>\n");
+
+ mutex_lock(&cache_chain_mutex);
+ list_for_each_entry(cachep, &cache_chain, next) {
+ if (cachep->memcg_params.memcg != memcg)
+ continue;
+
+ get_slab_counts(cachep, &c);
+
+ seq_printf(m, "%-17s %6lu %6lu %6u\n", cachep->name,
+ c.active_objs, c.num_objs, cachep->buffer_size);
+ }
+ mutex_unlock(&cache_chain_mutex);
+
+ return 0;
+}
+#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+
/*
* slabinfo_op - iterator that generates /proc/slabinfo
*
diff --git a/mm/slub.c b/mm/slub.c
index f5fc10c..c8a8cab 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4110,6 +4110,11 @@ struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
kfree(name);
return new;
}
+
+int mem_cgroup_slabinfo(struct mem_cgroup *memcg, struct seq_file *m)
+{
+ return 0;
+}
#endif
#ifdef CONFIG_SMP
--
1.7.7.6
|
|
|
|
| [PATCH v3 06/28] slab: use obj_size field of struct kmem_cache when not debugging [message #46531 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
The kmem controller needs to keep track of the object size of
a cache so it can later on create a per-memcg duplicate. Logic
to keep track of that already exists, but it is only enable while
debugging.
This patch makes it also available when the kmem controller code
is compiled in.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
---
include/linux/slab_def.h | 4 +++-
mm/slab.c | 37 ++++++++++++++++++++++++++-----------
2 files changed, 29 insertions(+), 12 deletions(-)
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index d41effe..cba3139 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -78,8 +78,10 @@ struct kmem_cache {
* variables contain the offset to the user object and its size.
*/
int obj_offset;
- int obj_size;
#endif /* CONFIG_DEBUG_SLAB */
+#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM)
+ int obj_size;
+#endif
/* 6) per-cpu/per-node data, touched during every alloc/free */
/*
diff --git a/mm/slab.c b/mm/slab.c
index 1057a32..41345f6 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -413,8 +413,28 @@ static void kmem_list3_init(struct kmem_list3 *parent)
#define STATS_INC_FREEMISS(x) do { } while (0)
#endif
-#if DEBUG
+#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM)
+static int obj_size(struct kmem_cache *cachep)
+{
+ return cachep->obj_size;
+}
+static void set_obj_size(struct kmem_cache *cachep, int size)
+{
+ cachep->obj_size = size;
+}
+
+#else
+static int obj_size(struct kmem_cache *cachep)
+{
+ return cachep->buffer_size;
+}
+
+static void set_obj_size(struct kmem_cache *cachep, int size)
+{
+}
+#endif
+#if DEBUG
/*
* memory layout of objects:
* 0 : objp
@@ -433,11 +453,6 @@ static int obj_offset(struct kmem_cache *cachep)
return cachep->obj_offset;
}
-static int obj_size(struct kmem_cache *cachep)
-{
- return cachep->obj_size;
-}
-
static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
{
BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
@@ -465,7 +480,6 @@ static void **dbg_userword(struct kmem_cache *cachep, void *objp)
#else
#define obj_offset(x) 0
-#define obj_size(cachep) (cachep->buffer_size)
#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
@@ -1555,9 +1569,9 @@ void __init kmem_cache_init(void)
*/
cache_cache.buffer_size = offsetof(struct kmem_cache, array[nr_cpu_ids]) +
nr_node_ids * sizeof(struct kmem_list3 *);
-#if DEBUG
- cache_cache.obj_size = cache_cache.buffer_size;
-#endif
+
+ set_obj_size(&cache_cache, cache_cache.buffer_size);
+
cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
cache_line_size());
cache_cache.reciprocal_buffer_size =
@@ -2418,8 +2432,9 @@ kmem_cache_create (const char *name, size_t size, size_t align,
goto oops;
cachep->nodelists = (struct kmem_list3 **)&cachep->array[nr_cpu_ids];
+
+ set_obj_size(cachep, size);
#if DEBUG
- cachep->obj_size = size;
/*
* Both debugging options require word-alignment which is calculated
--
1.7.7.6
|
|
|
|
| [PATCH v3 10/28] slab/slub: struct memcg_params [message #46532 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
For the kmem slab controller, we need to record some extra
information in the kmem_cache structure.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
---
include/linux/slab.h | 14 ++++++++++++++
include/linux/slab_def.h | 4 ++++
include/linux/slub_def.h | 3 +++
3 files changed, 21 insertions(+), 0 deletions(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index a595dce..dbf36b5 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -153,6 +153,20 @@ unsigned int kmem_cache_size(struct kmem_cache *);
#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
#endif
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+struct mem_cgroup_cache_params {
+ struct mem_cgroup *memcg;
+ int id;
+ atomic_t refcnt;
+
+#ifdef CONFIG_SLAB
+ /* Original cache parameters, used when creating a memcg cache */
+ size_t orig_align;
+
+#endif
+};
+#endif
+
/*
* Common kmalloc functions provided by all allocators
*/
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index cba3139..06e4a3e 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -83,6 +83,10 @@ struct kmem_cache {
int obj_size;
#endif
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ struct mem_cgroup_cache_params memcg_params;
+#endif
+
/* 6) per-cpu/per-node data, touched during every alloc/free */
/*
* We put array[] at the end of kmem_cache, because we want to size
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index c2f8c8b..5f5e942 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -102,6 +102,9 @@ struct kmem_cache {
#ifdef CONFIG_SYSFS
struct kobject kobj; /* For sysfs */
#endif
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ struct mem_cgroup_cache_params memcg_params;
+#endif
#ifdef CONFIG_NUMA
/*
--
1.7.7.6
|
|
|
|
| [PATCH v3 12/28] slab: pass memcg parameter to kmem_cache_create [message #46533 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
Allow a memcg parameter to be passed during cache creation.
Default function is created as a wrapper, passing NULL
to the memcg version. We only merge caches that belong
to the same memcg.
This code was mostly written by Suleiman Souhlal and
only adapted to my patchset, plus a couple of simplifications
[ v3: get_online_cpus need to be outside slab mutex. ]
[ also, register all caches created before FULL state ]
Signed-off-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
---
include/linux/slab_def.h | 7 ++++
mm/slab.c | 79 ++++++++++++++++++++++++++++++++++++----------
2 files changed, 69 insertions(+), 17 deletions(-)
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index 06e4a3e..7c0cdd6 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -102,6 +102,13 @@ struct kmem_cache {
*/
};
+static inline void store_orig_align(struct kmem_cache *cachep, int orig_align)
+{
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ cachep->memcg_params.orig_align = orig_align;
+#endif
+}
+
/* Size description struct for general caches. */
struct cache_sizes {
size_t cs_size;
diff --git a/mm/slab.c b/mm/slab.c
index 41345f6..8bff32a1 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1729,6 +1729,31 @@ void __init kmem_cache_init_late(void)
*/
}
+static int __init memcg_slab_register_all(void)
+{
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ struct kmem_cache *cachep;
+ struct cache_sizes *sizes;
+
+ sizes = malloc_sizes;
+
+ while (sizes->cs_size != ULONG_MAX) {
+ if (sizes->cs_cachep)
+ mem_cgroup_register_cache(NULL, sizes->cs_cachep);
+ if (sizes->cs_dmacachep)
+ mem_cgroup_register_cache(NULL, sizes->cs_dmacachep);
+ sizes++;
+ }
+
+ mutex_lock(&cache_chain_mutex);
+ list_for_each_entry(cachep, &cache_chain, next)
+ mem_cgroup_register_cache(NULL, cachep);
+
+ mutex_unlock(&cache_chain_mutex);
+#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+ return 0;
+}
+
static int __init cpucache_init(void)
{
int cpu;
@@ -1739,6 +1764,8 @@ static int __init cpucache_init(void)
for_each_online_cpu(cpu)
start_cpu_timer(cpu);
+ memcg_slab_register_all();
+
/* Done! */
g_cpucache_up = FULL;
return 0;
@@ -2287,14 +2314,15 @@ static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
* cacheline. This can be beneficial if you're counting cycles as closely
* as davem.
*/
-struct kmem_cache *
-kmem_cache_create (const char *name, size_t size, size_t align,
- unsigned long flags, void (*ctor)(void *))
+static struct kmem_cache *
+__kmem_cache_create(struct mem_cgroup *memcg, const char *name, size_t size,
+ size_t align, unsigned long flags, void (*ctor)(void *))
{
- size_t left_over, slab_size, ralign;
+ size_t left_over, orig_align, ralign, slab_size;
struct kmem_cache *cachep = NULL, *pc;
gfp_t gfp;
+ orig_align = align;
/*
* Sanity checks... these are all serious usage bugs.
*/
@@ -2305,15 +2333,6 @@ kmem_cache_create (const char *name, size_t size, size_t align,
BUG();
}
- /*
- * We use cache_chain_mutex to ensure a consistent view of
- * cpu_online_mask as well. Please see cpuup_callback
- */
- if (slab_is_available()) {
- get_online_cpus();
- mutex_lock(&cache_chain_mutex);
- }
-
list_for_each_entry(pc, &cache_chain, next) {
char tmp;
int res;
@@ -2331,7 +2350,7 @@ kmem_cache_create (const char *name, size_t size, size_t align,
continue;
}
- if (!strcmp(pc->name, name)) {
+ if (!memcg && !strcmp(pc->name, name)) {
printk(KERN_ERR
"kmem_cache_create: duplicate cache %s\n", name);
dump_stack();
@@ -2434,6 +2453,8 @@ kmem_cache_create (const char *name, size_t size, size_t align,
cachep->nodelists = (struct kmem_list3 **)&cachep->array[nr_cpu_ids];
set_obj_size(cachep, size);
+
+ store_orig_align(cachep, orig_align);
#if DEBUG
/*
@@ -2543,7 +2564,12 @@ kmem_cache_create (const char *name, size_t size, size_t align,
cachep->ctor = ctor;
cachep->name = name;
+ if (g_cpucache_up >= FULL)
+ mem_cgroup_register_cache(memcg, cachep);
+
+
if (setup_cpu_cache(cachep, gfp)) {
+ mem_cgroup_release_cache(cachep);
__kmem_cache_destroy(cachep);
cachep = NULL;
goto oops;
@@ -2565,10 +2591,27 @@ oops:
if (!cachep && (flags & SLAB_PANIC))
panic("kmem_cache_create(): failed to create slab `%s'\n",
name);
- if (slab_is_available()) {
- mutex_unlock(&cache_chain_mutex);
+ return cachep;
+}
+
+struct kmem_cache *
+kmem_cache_create(const char *name, size_t size, size_t align,
+ unsigned long flags, void (*ctor)(void *))
+{
+ struct kmem_cache *cachep;
+
+ /*
+ * We use cache_chain_mutex to ensure a consistent view of
+ * cpu_online_mask as well. Please see cpuup_callback
+ */
+ if (slab_is_available())
+ get_online_cpus();
+ mutex_lock(&cache_chain_mutex);
+ cachep = __kmem_cache_create(NULL, name, size, align, flags, ctor);
+ mutex_unlock(&cache_chain_mutex);
+ if (slab_is_available())
put_online_cpus();
- }
+
return cachep;
}
EXPORT_SYMBOL(kmem_cache_create);
@@ -2767,6 +2810,8 @@ void kmem_cache_destroy(struct kmem_cache *cachep)
if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
rcu_barrier();
+ mem_cgroup_release_cache(cachep);
+
__kmem_cache_destroy(cachep);
mutex_unlock(&cache_chain_mutex);
put_online_cpus();
--
1.7.7.6
|
|
|
|
| [PATCH v3 14/28] slab: create duplicate cache [message #46534 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
This patch provides kmem_cache_dup(), that duplicates
a cache for a memcg, preserving its creation properties.
Object size, alignment and flags are all respected.
An exception is the SLAB_PANIC flag, since cache creation
inside a memcg should not be fatal.
This code is mostly written by Suleiman Souhlal,
with some adaptations and simplifications by me.
[ v3: add get_online cpus before the slab mutex ]
Signed-off-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
---
mm/slab.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 44 insertions(+), 0 deletions(-)
diff --git a/mm/slab.c b/mm/slab.c
index 8bff32a1..e2227de 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -301,6 +301,8 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int len,
int node);
static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp);
static void cache_reap(struct work_struct *unused);
+static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
+ int batchcount, int shared, gfp_t gfp);
/*
* This function must be completely optimized away if a constant is passed to
@@ -2616,6 +2618,42 @@ kmem_cache_create(const char *name, size_t size, size_t align,
}
EXPORT_SYMBOL(kmem_cache_create);
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
+ struct kmem_cache *cachep)
+{
+ struct kmem_cache *new;
+ unsigned long flags;
+ char *name;
+
+ name = mem_cgroup_cache_name(memcg, cachep);
+ if (!name)
+ return NULL;
+
+ flags = cachep->flags & ~(SLAB_PANIC|CFLGS_OFF_SLAB);
+
+ get_online_cpus();
+ mutex_lock(&cache_chain_mutex);
+ new = __kmem_cache_create(memcg, name, obj_size(cachep),
+ cachep->memcg_params.orig_align, flags, cachep->ctor);
+
+ if (new == NULL) {
+ kfree(name);
+ goto out;
+ }
+
+ if ((cachep->limit != new->limit) ||
+ (cachep->batchcount != new->batchcount) ||
+ (cachep->shared != new->shared))
+ do_tune_cpucache(new, cachep->limit, cachep->batchcount,
+ cachep->shared, GFP_KERNEL);
+out:
+ mutex_unlock(&cache_chain_mutex);
+ put_online_cpus();
+ return new;
+}
+#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+
#if DEBUG
static void check_irq_off(void)
{
@@ -2811,6 +2849,12 @@ void kmem_cache_destroy(struct kmem_cache *cachep)
rcu_barrier();
mem_cgroup_release_cache(cachep);
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ /* memcg cache: free the name string. Doing it here saves us
+ * a pointer to it outside the slab code */
+ if (cachep->memcg_params.id == -1)
+ kfree(cachep->name);
+#endif
__kmem_cache_destroy(cachep);
mutex_unlock(&cache_chain_mutex);
--
1.7.7.6
|
|
|
|
| [PATCH v3 15/28] slub: always get the cache from its page in kfree [message #46535 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
struct page already have this information. If we start chaining
caches, this information will always be more trustworthy than
whatever is passed into the function
A parent pointer is added to the slub structure, so we can make sure
the freeing comes from either the right slab, or from its rightful
parent.
[ v3: added parent testing with VM_BUG_ON ]
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
---
include/linux/slab.h | 3 +++
include/linux/slub_def.h | 18 ++++++++++++++++++
mm/slub.c | 7 ++++++-
3 files changed, 27 insertions(+), 1 deletions(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index e73ef71..724c143 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -164,6 +164,9 @@ struct mem_cgroup_cache_params {
size_t orig_align;
#endif
+#ifdef CONFIG_DEBUG_VM
+ struct kmem_cache *parent;
+#endif
};
#endif
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 5f5e942..f822ca2 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -115,6 +115,24 @@ struct kmem_cache {
struct kmem_cache_node *node[MAX_NUMNODES];
};
+static inline void slab_set_parent(struct kmem_cache *s,
+ struct kmem_cache *parent)
+{
+#if defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM) && defined(CONFIG_DEBUG_VM)
+ s->memcg_params.parent = parent;
+#endif
+}
+
+static inline bool slab_is_parent(struct kmem_cache *s,
+ struct kmem_cache *candidate)
+{
+#if defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM) && defined(CONFIG_DEBUG_VM)
+ return candidate == s->memcg_params.parent;
+#else
+ return false;
+#endif
+}
+
/*
* Kmalloc subsystem.
*/
diff --git a/mm/slub.c b/mm/slub.c
index 0eb9e72..640872f 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2598,10 +2598,14 @@ redo:
void kmem_cache_free(struct kmem_cache *s, void *x)
{
struct page *page;
+ bool slab_match;
page = virt_to_head_page(x);
- slab_free(s, page, x, _RET_IP_);
+ slab_match = (page->slab == s) | slab_is_parent(page->slab, s);
+ VM_BUG_ON(!slab_match);
+
+ slab_free(page->slab, page, x, _RET_IP_);
trace_kmem_cache_free(_RET_IP_, x);
}
@@ -4027,6 +4031,7 @@ struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
down_write(&slub_lock);
s->refcount++;
up_write(&slub_lock);
+ slab_set_parent(new, s);
}
/* slub internals is expected to have held a copy of it */
kfree(name);
--
1.7.7.6
|
|
|
|
| [PATCH v3 17/28] skip memcg kmem allocations in specified code regions [message #46536 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
This patch creates a mechanism that skip memcg allocations during
certain pieces of our core code. It basically works in the same way
as preempt_disable()/preempt_enable(): By marking a region under
which all allocations will be accounted to the root memcg.
We need this to prevent races in early cache creation, when we
allocate data using caches that are not necessarily created already.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Suleiman Souhlal <suleiman@google.com>
---
include/linux/sched.h | 1 +
mm/memcontrol.c | 25 +++++++++++++++++++++++++
2 files changed, 26 insertions(+), 0 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 81a173c..0761dda 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1613,6 +1613,7 @@ struct task_struct {
unsigned long nr_pages; /* uncharged usage */
unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
} memcg_batch;
+ unsigned int memcg_kmem_skip_account;
#endif
#ifdef CONFIG_HAVE_HW_BREAKPOINT
atomic_t ptrace_bp_refcnt;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 44589fb..f3a3812 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -479,6 +479,21 @@ struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
EXPORT_SYMBOL(tcp_proto_cgroup);
#endif /* CONFIG_INET */
+static void memcg_stop_kmem_account(void)
+{
+ if (!current->mm)
+ return;
+
+ current->memcg_kmem_skip_account++;
+}
+
+static void memcg_resume_kmem_account(void)
+{
+ if (!current->mm)
+ return;
+
+ current->memcg_kmem_skip_account--;
+}
char *mem_cgroup_cache_name(struct mem_cgroup *memcg, struct kmem_cache *cachep)
{
char *name;
@@ -540,7 +555,9 @@ static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
if (new_cachep)
goto out;
+ memcg_stop_kmem_account();
new_cachep = kmem_cache_dup(memcg, cachep);
+ memcg_resume_kmem_account();
if (new_cachep == NULL) {
new_cachep = cachep;
@@ -631,7 +648,9 @@ static void memcg_create_cache_enqueue(struct mem_cgroup *memcg,
if (!css_tryget(&memcg->css))
return;
+ memcg_stop_kmem_account();
cw = kmalloc(sizeof(struct create_work), GFP_NOWAIT);
+ memcg_resume_kmem_account();
if (cw == NULL) {
css_put(&memcg->css);
return;
@@ -666,6 +685,9 @@ struct kmem_cache *__mem_cgroup_get_kmem_cache(struct kmem_cache *cachep,
int idx;
struct task_struct *p;
+ if (!current->mm || current->memcg_kmem_skip_account)
+ return cachep;
+
gfp |= cachep->allocflags;
if (cachep->memcg_params.memcg)
@@ -700,6 +722,9 @@ bool __mem_cgroup_new_kmem_page(struct page *page, gfp_t gfp)
if (!current->mm || in_interrupt())
return true;
+ if (!current->mm || current->memcg_kmem_skip_account)
+ return true;
+
rcu_read_lock();
p = rcu_dereference(current->mm->owner);
memcg = mem_cgroup_from_task(p);
--
1.7.7.6
|
|
|
|
| [PATCH v3 13/28] slub: create duplicate cache [message #46537 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
This patch provides kmem_cache_dup(), that duplicates
a cache for a memcg, preserving its creation properties.
Object size, alignment and flags are all respected.
When a duplicate cache is created, the parent cache cannot
be destructed during the child lifetime. To assure this,
its reference count is increased if the cache creation
succeeds.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Suleiman Souhlal <suleiman@google.com>
---
include/linux/memcontrol.h | 2 ++
include/linux/slab.h | 2 ++
mm/memcontrol.c | 17 +++++++++++++++++
mm/slub.c | 32 ++++++++++++++++++++++++++++++++
4 files changed, 53 insertions(+), 0 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 99e14b9..f93021a 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -445,6 +445,8 @@ int memcg_css_id(struct mem_cgroup *memcg);
void mem_cgroup_register_cache(struct mem_cgroup *memcg,
struct kmem_cache *s);
void mem_cgroup_release_cache(struct kmem_cache *cachep);
+extern char *mem_cgroup_cache_name(struct mem_cgroup *memcg,
+ struct kmem_cache *cachep);
#else
static inline void mem_cgroup_register_cache(struct mem_cgroup *memcg,
struct kmem_cache *s)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 1386650..e73ef71 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -322,6 +322,8 @@ extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
#define MAX_KMEM_CACHE_TYPES 400
+extern struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
+ struct kmem_cache *cachep);
#else
#define MAX_KMEM_CACHE_TYPES 0
#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index dacd1fb..4689034 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -467,6 +467,23 @@ struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
EXPORT_SYMBOL(tcp_proto_cgroup);
#endif /* CONFIG_INET */
+char *mem_cgroup_cache_name(struct mem_cgroup *memcg, struct kmem_cache *cachep)
+{
+ char *name;
+ struct dentry *dentry;
+
+ rcu_read_lock();
+ dentry = rcu_dereference(memcg->css.cgroup->dentry);
+ rcu_read_unlock();
+
+ BUG_ON(dentry == NULL);
+
+ name = kasprintf(GFP_KERNEL, "%s(%d:%s)",
+ cachep->name, css_id(&memcg->css), dentry->d_name.name);
+
+ return name;
+}
+
struct ida cache_types;
void mem_cgroup_register_cache(struct mem_cgroup *memcg,
diff --git a/mm/slub.c b/mm/slub.c
index d79740c..0eb9e72 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4002,6 +4002,38 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size,
}
EXPORT_SYMBOL(kmem_cache_create);
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
+ struct kmem_cache *s)
+{
+ char *name;
+ struct kmem_cache *new;
+
+ name = mem_cgroup_cache_name(memcg, s);
+ if (!name)
+ return NULL;
+
+ new = kmem_cache_create_memcg(memcg, name, s->objsize, s->align,
+ (s->allocflags & ~SLAB_PANIC), s->ctor);
+
+ /*
+ * We increase the reference counter in the parent cache, to
+ * prevent it from being deleted. If kmem_cache_destroy() is
+ * called for the root cache before we call it for a child cache,
+ * it will be queued for destruction when we finally drop the
+ * reference on the child cache.
+ */
+ if (new) {
+ down_write(&slub_lock);
+ s->refcount++;
+ up_write(&slub_lock);
+ }
+ /* slub internals is expected to have held a copy of it */
+ kfree(name);
+ return new;
+}
+#endif
+
#ifdef CONFIG_SMP
/*
* Use the cpu notifier to insure that the cpu slabs are flushed when
--
1.7.7.6
|
|
|
|
| [PATCH v3 11/28] slub: consider a memcg parameter in kmem_create_cache [message #46538 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
Allow a memcg parameter to be passed during cache creation.
The slub allocator will only merge caches that belong to
the same memcg.
Default function is created as a wrapper, passing NULL
to the memcg version. We only merge caches that belong
to the same memcg.
>From the memcontrol.c side, 3 helper functions are created:
1) memcg_css_id: because slub needs a unique cache name
for sysfs. Since this is visible, but not the canonical
location for slab data, the cache name is not used, the
css_id should suffice.
2) mem_cgroup_register_cache: is responsible for assigning
a unique index to each cache, and other general purpose
setup. The index is only assigned for the root caches. All
others are assigned index == -1.
3) mem_cgroup_release_cache: can be called from the root cache
destruction, and will release the index for
other caches.
We can't assign indexes until the basic slab is up and running
this is because the ida subsystem will itself call slab functions
such as kmalloc a couple of times. Because of that, we have
a late_initcall that scan all caches and register them after the
kernel is booted up. Only caches registered after that receive
their index right away.
This index mechanism was developed by Suleiman Souhlal.
Changed to a idr/ida based approach based on suggestion
from Kamezawa.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Suleiman Souhlal <suleiman@google.com>
---
include/linux/memcontrol.h | 14 ++++++++++
include/linux/slab.h | 6 ++++
mm/memcontrol.c | 27 ++++++++++++++++++++
mm/slub.c | 58 ++++++++++++++++++++++++++++++++++++++++---
4 files changed, 101 insertions(+), 4 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index f94efd2..99e14b9 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -26,6 +26,7 @@ struct mem_cgroup;
struct page_cgroup;
struct page;
struct mm_struct;
+struct kmem_cache;
/* Stats that can be updated by kernel. */
enum mem_cgroup_page_stat_item {
@@ -440,7 +441,20 @@ struct sock;
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
void sock_update_memcg(struct sock *sk);
void sock_release_memcg(struct sock *sk);
+int memcg_css_id(struct mem_cgroup *memcg);
+void mem_cgroup_register_cache(struct mem_cgroup *memcg,
+ struct kmem_cache *s);
+void mem_cgroup_release_cache(struct kmem_cache *cachep);
#else
+static inline void mem_cgroup_register_cache(struct mem_cgroup *memcg,
+ struct kmem_cache *s)
+{
+}
+
+static inline void mem_cgroup_release_cache(struct kmem_cache *cachep)
+{
+}
+
static inline void sock_update_memcg(struct sock *sk)
{
}
diff --git a/include/linux/slab.h b/include/linux/slab.h
index dbf36b5..1386650 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -320,6 +320,12 @@ extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
__kmalloc(size, flags)
#endif /* DEBUG_SLAB */
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+#define MAX_KMEM_CACHE_TYPES 400
+#else
+#define MAX_KMEM_CACHE_TYPES 0
+#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+
#ifdef CONFIG_NUMA
/*
* kmalloc_node_track_caller is a special version of kmalloc_node that
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b6bac5f..dacd1fb 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -323,6 +323,11 @@ struct mem_cgroup {
#endif
};
+int memcg_css_id(struct mem_cgroup *memcg)
+{
+ return css_id(&memcg->css);
+}
+
/* Stuffs for move charges at task migration. */
/*
* Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
@@ -461,6 +466,27 @@ struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
}
EXPORT_SYMBOL(tcp_proto_cgroup);
#endif /* CONFIG_INET */
+
+struct ida cache_types;
+
+void mem_cgroup_register_cache(struct mem_cgroup *memcg,
+ struct kmem_cache *cachep)
+{
+ int id = -1;
+
+ cachep->memcg_params.memcg = memcg;
+
+ if (!memcg)
+ id = ida_simple_get(&cache_types, 0, MAX_KMEM_CACHE_TYPES,
+ GFP_KERNEL);
+ cachep->memcg_params.id = id;
+}
+
+void mem_cgroup_release_cache(struct kmem_cache *cachep)
+{
+ if (cachep->memcg_params.id != -1)
+ ida_simple_remove(&cache_types, cachep->memcg_params.id);
+}
#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
static void drain_all_stock_async(struct mem_cgroup *memcg);
@@ -5053,6 +5079,7 @@ mem_cgroup_create(struct cgroup *cont)
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys,
kmem_cgroup_files));
+ ida_init(&cache_types);
#endif
if (mem_cgroup_soft_limit_tree_init())
diff --git a/mm/slub.c b/mm/slub.c
index ffe13fd..d79740c 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -32,6 +32,7 @@
#include <linux/prefetch.h>
#include <trace/events/kmem.h>
+#include <linux/memcontrol.h>
/*
* Lock order:
@@ -3193,6 +3194,7 @@ void kmem_cache_destroy(struct kmem_cache *s)
s->refcount--;
if (!s->refcount) {
list_del(&s->list);
+ mem_cgroup_release_cache(s);
up_write(&slub_lock);
if (kmem_cache_close(s)) {
printk(KERN_ERR "SLUB %s: %s called for cache that "
@@ -3880,7 +3882,7 @@ static int slab_unmergeable(struct kmem_cache *s)
return 0;
}
-static struct kmem_cache *find_mergeable(size_t size,
+static struct kmem_cache *find_mergeable(struct mem_cgroup *memcg, size_t size,
size_t align, unsigned long flags, const char *name,
void (*ctor)(void *))
{
@@ -3916,13 +3918,19 @@ static struct kmem_cache *find_mergeable(size_t size,
if (s->size - size >= sizeof(void *))
continue;
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ if (memcg && s->memcg_params.memcg != memcg)
+ continue;
+#endif
+
return s;
}
return NULL;
}
-struct kmem_cache *kmem_cache_create(const char *name, size_t size,
- size_t align, unsigned long flags, void (*ctor)(void *))
+struct kmem_cache *
+kmem_cache_create_memcg(struct mem_cgroup *memcg, const char *name, size_t size,
+ size_t align, unsigned long flags, void (*ctor)(void *))
{
struct kmem_cache *s;
char *n;
@@ -3930,8 +3938,12 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size,
if (WARN_ON(!name))
return NULL;
+#ifndef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ WARN_ON(memcg != NULL);
+#endif
+
down_write(&slub_lock);
- s = find_mergeable(size, align, flags, name, ctor);
+ s = find_mergeable(memcg, size, align, flags, name, ctor);
if (s) {
s->refcount++;
/*
@@ -3959,6 +3971,8 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size,
size, align, flags, ctor)) {
list_add(&s->list, &slab_caches);
up_write(&slub_lock);
+ if (slab_state >= SYSFS)
+ mem_cgroup_register_cache(memcg, s);
if (sysfs_slab_add(s)) {
down_write(&slub_lock);
list_del(&s->list);
@@ -3980,6 +3994,12 @@ err:
s = NULL;
return s;
}
+
+struct kmem_cache *kmem_cache_create(const char *name, size_t size,
+ size_t align, unsigned long flags, void (*ctor)(void *))
+{
+ return kmem_cache_create_memcg(NULL, name, size, align, flags, ctor);
+}
EXPORT_SYMBOL(kmem_cache_create);
#ifdef CONFIG_SMP
@@ -5273,6 +5293,11 @@ static char *create_unique_id(struct kmem_cache *s)
if (p != name + 1)
*p++ = '-';
p += sprintf(p, "%07d", s->size);
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ if (s->memcg_params.memcg)
+ p += sprintf(p, "-%08d", memcg_css_id(s->memcg_params.memcg));
+#endif
BUG_ON(p > name + ID_STR_LENGTH - 1);
return name;
}
@@ -5375,6 +5400,30 @@ static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
return 0;
}
+static void __init memcg_slab_register_all(void)
+{
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ struct kmem_cache *s;
+ int i;
+
+ for (i = 0; i < SLUB_PAGE_SHIFT; i++) {
+ struct kmem_cache *s;
+ s = kmalloc_caches[i];
+ if (s)
+ mem_cgroup_register_cache(NULL, s);
+ s = kmalloc_dma_caches[i];
+ if (s)
+ mem_cgroup_register_cache(NULL, s);
+ }
+
+ list_for_each_entry(s, &slab_caches, list)
+ mem_cgroup_register_cache(NULL, s);
+
+#endif
+}
+
+
static int __init slab_sysfs_init(void)
{
struct kmem_cache *s;
@@ -5409,6 +5458,7 @@ static int __init slab_sysfs_init(void)
kfree(al);
}
+ memcg_slab_register_all();
up_write(&slub_lock);
resiliency_test();
return 0;
--
1.7.7.6
...
|
|
|
|
| [PATCH v3 26/28] slub: track all children of a kmem cache [message #46539 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
When we destroy a cache (like for instance, if we're unloading a module)
we need to go through the list of memcg caches and destroy them as well.
The caches are expected to be empty by themselves, so nothing is changed
here. All previous guarantees are kept and no new guarantees are given.
So given all memcg caches are expected to be empty - even though they are
likely to be hanging around in the system, we just need to scan a list of
sibling caches, and destroy each one of them.
This is very similar to the work done by Suleiman for the slab.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Suleiman Souhlal <suleiman@google.com>
---
mm/slub.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++--------
1 files changed, 55 insertions(+), 9 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index 4c29e5f..8151353 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3254,6 +3254,54 @@ static inline int kmem_cache_close(struct kmem_cache *s)
return 0;
}
+static void kmem_cache_destroy_unlocked(struct kmem_cache *s)
+{
+ mem_cgroup_release_cache(s);
+ if (kmem_cache_close(s)) {
+ printk(KERN_ERR
+ "SLUB %s: %s called for cache that still has objects.\n",
+ s->name, __func__);
+ dump_stack();
+ }
+
+ if (s->flags & SLAB_DESTROY_BY_RCU)
+ rcu_barrier();
+ sysfs_slab_remove(s);
+}
+
+static void kmem_cache_destroy_memcg_children(struct kmem_cache *s)
+{
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ struct mem_cgroup_cache_params *p, *tmp, *this;
+ struct kmem_cache *c;
+ int id = s->memcg_params.id;
+
+ /* Not a parent cache */
+ if (id == -1)
+ return ;
+
+ this = &s->memcg_params;
+ mem_cgroup_flush_cache_create_queue();
+ list_for_each_entry_safe(p, tmp, &this->sibling_list, sibling_list) {
+ c = container_of(p, struct kmem_cache, memcg_params);
+ /* We never added the main cache to the sibling list */
+ if (WARN_ON(c == s))
+ continue;
+
+ c->refcount--;
+ if (c->refcount)
+ continue;
+
+ list_del(&c->list);
+ list_del(&c->memcg_params.sibling_list);
+ s->refcount--; /* parent reference */
+ up_write(&slub_lock);
+ mem_cgroup_remove_child_kmem_cache(c, id);
+ kmem_cache_destroy_unlocked(c);
+ down_write(&slub_lock);
+ }
+#endif
+}
/*
* Close a cache and release the kmem_cache structure
* (must be used for caches created using kmem_cache_create)
@@ -3261,19 +3309,15 @@ static inline int kmem_cache_close(struct kmem_cache *s)
void kmem_cache_destroy(struct kmem_cache *s)
{
down_write(&slub_lock);
+ kmem_cache_destroy_memcg_children(s);
s->refcount--;
if (!s->refcount) {
list_del(&s->list);
- mem_cgroup_release_cache(s);
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ list_del(&s->memcg_params.sibling_list);
+#endif
up_write(&slub_lock);
- if (kmem_cache_close(s)) {
- printk(KERN_ERR "SLUB %s: %s called for cache that "
- "still has objects.\n", s->name, __func__);
- dump_stack();
- }
- if (s->flags & SLAB_DESTROY_BY_RCU)
- rcu_barrier();
- sysfs_slab_remove(s);
+ kmem_cache_destroy_unlocked(s);
} else
up_write(&slub_lock);
}
@@ -4102,6 +4146,8 @@ struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
*/
if (new) {
down_write(&slub_lock);
+ list_add(&new->memcg_params.sibling_list,
+ &s->memcg_params.sibling_list);
s->refcount++;
up_write(&slub_lock);
slab_set_parent(new, s);
--
1.7.7.6
|
|
|
|
| [PATCH v3 28/28] Documentation: add documentation for slab tracker for memcg [message #46540 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
In a separate patch, to aid reviewers.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Suleiman Souhlal <suleiman@google.com>
CC: Randy Dunlap <rdunlap@xenotime.net>
---
Documentation/cgroups/memory.txt | 33 +++++++++++++++++++++++++++++++++
1 files changed, 33 insertions(+), 0 deletions(-)
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index 4c95c00..9accaa1 100644
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt
@@ -75,6 +75,12 @@ Brief summary of control files.
memory.kmem.tcp.limit_in_bytes # set/show hard limit for tcp buf memory
memory.kmem.tcp.usage_in_bytes # show current tcp buf memory allocation
+ memory.kmem.limit_in_bytes # set/show hard limit for general kmem memory
+ memory.kmem.usage_in_bytes # show current general kmem memory allocation
+ memory.kmem.failcnt # show current number of kmem limit hits
+ memory.kmem.max_usage_in_bytes # show max kmem usage
+ memory.kmem.slabinfo # show cgroup-specific slab usage information
+
1. History
The memory controller has a long history. A request for comments for the memory
@@ -271,6 +277,14 @@ cgroup may or may not be accounted.
Currently no soft limit is implemented for kernel memory. It is future work
to trigger slab reclaim when those limits are reached.
+Kernel memory is not accounted until it is limited. Users that want to just
+track kernel memory usage can set the limit value to a big enough value so
+the limit is guaranteed to never hit. A kernel memory limit bigger than the
+current memory limit will have this effect as well.
+
+This guarantes that this extension is backwards compatible to any previous
+memory cgroup version.
+
2.7.1 Current Kernel Memory resources accounted
* sockets memory pressure: some sockets protocols have memory pressure
@@ -279,6 +293,24 @@ per cgroup, instead of globally.
* tcp memory pressure: sockets memory pressure for the tcp protocol.
+* slab/kmalloc:
+
+When slab memory is tracked (memory.kmem.limit_in_bytes != -1ULL), both
+memory.kmem.usage_in_bytes and memory.usage_in_bytes are updated. When
+memory.kmem.limit_in_bytes is left alone, no tracking of slab caches takes
+place.
+
+Because a slab page is shared among many tasks, it is not possible to take
+any meaningful action upon task migration. Slabs created in a cgroup stay
+around until the cgroup is destructed. Information about the slabs used
+by the cgroup is displayed in the cgroup file memory.kmem.slabinfo. The format
+of this file is and should remain compatible with /proc/slabinfo.
+
+Upon cgroup destruction, slabs that holds no live references are destructed.
+Workers are fired to destroy the remaining caches as they objects are freed.
+
+Memory used by dead caches are shown in the proc file /proc/dead_slabinfo
+
3. User Interface
0. Configuration
@@ -287,6 +319,7 @@ a. Enable CONFIG_CGROUPS
b. Enable CONFIG_RESOURCE_COUNTERS
c. Enable CONFIG_CGROUP_MEM_RES_CTLR
d. Enable CONFIG_CGROUP_MEM_RES_CTLR_SWAP (to use swap extension)
+d. Enable CONFIG_CGROUP_MEM_RES_CTLR_KMEM (to use experimental kmem extension)
1. Prepare the cgroups (see cgroups.txt, Why are cgroups needed?)
# mount -t tmpfs none /sys/fs/cgroup
--
1.7.7.6
|
|
|
|
| [PATCH v3 23/28] slab: Track all the memcg children of a kmem_cache. [message #46541 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
This enables us to remove all the children of a kmem_cache being
destroyed, if for example the kernel module it's being used in
gets unloaded. Otherwise, the children will still point to the
destroyed parent.
We also use this to propagate /proc/slabinfo settings to all
the children of a cache, when, for example, changing its
batchsize.
Code is inspired by Suleiman's, with adaptations to
the patchset and simplifications by me.
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
---
include/linux/memcontrol.h | 1 +
include/linux/slab.h | 1 +
mm/memcontrol.c | 13 ++++++++-
mm/slab.c | 61 +++++++++++++++++++++++++++++++++++++++++++-
4 files changed, 73 insertions(+), 3 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index df049e1..63113de 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -465,6 +465,7 @@ extern struct static_key mem_cgroup_kmem_enabled_key;
#define mem_cgroup_kmem_on static_key_false(&mem_cgroup_kmem_enabled_key)
void mem_cgroup_destroy_cache(struct kmem_cache *cachep);
+void mem_cgroup_remove_child_kmem_cache(struct kmem_cache *cachep, int id);
#else
static inline void mem_cgroup_register_cache(struct mem_cgroup *memcg,
struct kmem_cache *s)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 25f073e..714aeab 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -172,6 +172,7 @@ struct mem_cgroup_cache_params {
struct kmem_cache *parent;
#endif
struct list_head destroyed_list; /* Used when deleting memcg cache */
+ struct list_head sibling_list;
};
#endif
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e2576c5..08f3c3e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -542,10 +542,11 @@ void mem_cgroup_register_cache(struct mem_cgroup *memcg,
cachep->memcg_params.memcg = memcg;
- if (!memcg)
+ if (!memcg) {
id = ida_simple_get(&cache_types, 0, MAX_KMEM_CACHE_TYPES,
GFP_KERNEL);
- else
+ INIT_LIST_HEAD(&cachep->memcg_params.sibling_list);
+ } else
INIT_LIST_HEAD(&cachep->memcg_params.destroyed_list);
cachep->memcg_params.id = id;
}
@@ -845,6 +846,14 @@ struct kmem_cache *__mem_cgroup_get_kmem_cache(struct kmem_cache *cachep,
}
EXPORT_SYMBOL(__mem_cgroup_get_kmem_cache);
+void mem_cgroup_remove_child_kmem_cache(struct kmem_cache *cachep, int id)
+{
+ mutex_lock(&memcg_cache_mutex);
+ cachep->memcg_params.memcg->slabs[id] = NULL;
+ mutex_unlock(&memcg_cache_mutex);
+ mem_cgroup_put(cachep->memcg_params.memcg);
+}
+
bool __mem_cgroup_new_kmem_page(struct page *page, gfp_t gfp)
{
struct mem_cgroup *memcg;
diff --git a/mm/slab.c b/mm/slab.c
index 59f1027..cb409ae 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2661,6 +2661,8 @@ struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
goto out;
}
+ list_add(&new->memcg_params.sibling_list,
+ &cachep->memcg_params.sibling_list);
if ((cachep->limit != new->limit) ||
(cachep->batchcount != new->batchcount) ||
(cachep->shared != new->shared))
@@ -2829,6 +2831,33 @@ int kmem_cache_shrink(struct kmem_cache *cachep)
}
EXPORT_SYMBOL(kmem_cache_shrink);
+static void kmem_cache_destroy_memcg_children(struct kmem_cache *cachep)
+{
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ struct kmem_cache *c;
+ struct mem_cgroup_cache_params *p, *tmp;
+ int id = cachep->memcg_params.id;
+
+ if (id == -1)
+ return;
+
+ mutex_lock(&cache_chain_mutex);
+ list_for_each_entry_safe(p, tmp,
+ &cachep->memcg_params.sibling_list, sibling_list) {
+ c = container_of(p, struct kmem_cache, memcg_params);
+ if (WARN_ON(c == cachep))
+ continue;
+
+ mutex_unlock(&cache_chain_mutex);
+ BUG_ON(c->memcg_params.id != -1);
+ mem_cgroup_remove_child_kmem_cache(c, id);
+ kmem_cache_destroy(c);
+ mutex_lock(&cache_chain_mutex);
+ }
+ mutex_unlock(&cache_chain_mutex);
+#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+}
+
/**
* kmem_cache_destroy - delete a cache
* @cachep: the cache to destroy
@@ -2849,6 +2878,9 @@ void kmem_cache_destroy(struct kmem_cache *cachep)
{
BUG_ON(!cachep || in_interrupt());
+ /* Destroy all the children caches if we aren't a memcg cache */
+ kmem_cache_destroy_memcg_children(cachep);
+
/* Find the cache in the chain of caches. */
get_online_cpus();
mutex_lock(&cache_chain_mutex);
@@ -2869,6 +2901,7 @@ void kmem_cache_destroy(struct kmem_cache *cachep)
mem_cgroup_release_cache(cachep);
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ list_del(&cachep->memcg_params.sibling_list);
/* memcg cache: free the name string. Doing it here saves us
* a pointer to it outside the slab code */
if (cachep->memcg_params.id == -1)
@@ -4243,7 +4276,7 @@ static void do_ccupdate_local(void *info)
}
/* Always called with the cache_chain_mutex held */
-static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
+static int __do_tune_cpucache(struct kmem_cache *cachep, int limit,
int batchcount, int shared, gfp_t gfp)
{
struct ccupdate_struct *new;
@@ -4286,6 +4319,32 @@ static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
return alloc_kmemlist(cachep, gfp);
}
+static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
+ int batchcount, int shared, gfp_t gfp)
+{
+ int ret;
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ struct kmem_cache *c;
+ struct mem_cgroup_cache_params *p;
+#endif
+
+ ret = __do_tune_cpucache(cachep, limit, batchcount, shared, gfp);
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+ if (g_cpucache_up < FULL)
+ return ret;
+
+ if ((ret < 0) || (cachep->memcg_params.id == -1))
+ return ret;
+
+ list_for_each_entry(p, &cachep->memcg_params.sibling_list, sibling_list) {
+ c = container_of(p, struct kmem_cache, memcg_params);
+ /* return value determined by the parent cache only */
+ __do_tune_cpucache(c, limit, batchcount, shared, gfp);
+ }
+#endif
+ return ret;
+}
+
/* Called with cache_chain_mutex held always */
static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp)
{
--
1.7.7.6
|
|
|
|
| [PATCH v3 27/28] memcg: propagate kmem limiting information to children [message #46542 is a reply to message #46517] |
Fri, 25 May 2012 13:03 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
The current memcg slab cache management fails to present satisfatory hierarchical
behavior in the following scenario:
-> /cgroups/memory/A/B/C
* kmem limit set at A
* A and B empty taskwise
* bash in C does find /
Because kmem_accounted is a boolean that was not set for C, no accounting
would be done. This is, however, not what we expect.
The basic idea, is that when a cgroup is limited, we walk the tree
upwards (something Kame and I already thought about doing for other purposes),
and make sure that we store the information about the parent being limited in
kmem_accounted (that is turned into a bitmap: two booleans would not be space
efficient). The code for that is taken from sched/core.c. My reasons for not
putting it into a common place is to dodge the type issues that would arise
from a common implementation between memcg and the scheduler - but I think
that it should ultimately happen, so if you want me to do it now, let me
know.
We do the reverse operation when a formerly limited cgroup becomes unlimited.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Christoph Lameter <cl@linux.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Michal Hocko <mhocko@suse.cz>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Suleiman Souhlal <suleiman@google.com>
---
mm/memcontrol.c | 147 +++++++++++++++++++++++++++++++++++++++++++++++++------
1 files changed, 131 insertions(+), 16 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3e99c69..7572cb1 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -259,6 +259,9 @@ struct mem_cgroup {
* the counter to account for kernel memory usage.
*/
struct res_counter kmem;
+
+ struct list_head children;
+ struct list_head siblings;
/*
* Per cgroup active and inactive list, similar to the
* per zone LRU lists.
@@ -274,7 +277,11 @@ struct mem_cgroup {
* Should the accounting and control be hierarchical, per subtree?
*/
bool use_hierarchy;
- bool kmem_accounted;
+ /*
+ * bit0: accounted by this cgroup
+ * bit1: accounted by a parent.
+ */
+ volatile unsigned long kmem_accounted;
bool oom_lock;
atomic_t under_oom;
@@ -332,6 +339,9 @@ struct mem_cgroup {
#endif
};
+#define KMEM_ACCOUNTED_THIS 0
+#define KMEM_ACCOUNTED_PARENT 1
+
int memcg_css_id(struct mem_cgroup *memcg)
{
return css_id(&memcg->css);
@@ -474,7 +484,7 @@ void sock_release_memcg(struct sock *sk)
static void disarm_static_keys(struct mem_cgroup *memcg)
{
- if (memcg->kmem_accounted)
+ if (test_bit(KMEM_ACCOUNTED_THIS, &memcg->kmem_accounted))
static_key_slow_dec(&mem_cgroup_kmem_enabled_key);
/*
* This check can't live in kmem destruction function,
@@ -4472,6 +4482,110 @@ static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft,
len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val);
return simple_read_from_buffer(buf, nbytes, ppos, str, len);
}
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+typedef int (*memcg_visitor)(struct mem_cgroup*, void *);
+
+/*
+ * This is mostly "inspired" by the code in sched/core.c. I decided to copy it,
+ * instead of factoring it, because of all the typing issues we'd run into.
+ * In particular, grabbing the parent is very different for memcg, because we
+ * may or may not have hierarchy, while cpu cgroups always do. That would lead
+ * to either indirect calls - this is not a fast path for us, but can be for
+ * the scheduler - or a big and ugly macro.
+ *
+ * If we ever get rid of hierarchy, we could iterate over struct cgroup, and
+ * then it would cease to be a problem.
+ */
+int walk_tree_from(struct mem_cgroup *from,
+ memcg_visitor down, memcg_visitor up, void *data)
+{
+ struct mem_cgroup *parent, *child;
+ int ret;
+
+
+ parent = from;
+down:
+ ret = (*down)(parent, data);
+ if (ret)
+ goto out;
+
+ list_for_each_entry_rcu(child, &parent->children, siblings) {
+ parent = child;
+ goto down;
+
+up:
+ continue;
+ }
+ ret = (*up)(parent, data);
+ if (ret || parent == from)
+ goto out;
+
+ child = parent;
+ parent = parent_mem_cgroup(parent);
+ if (parent)
+ goto up;
+out:
+ return ret;
+}
+
+static int memcg_nop(struct mem_cgroup *memcg, void *data)
+{
+ return 0;
+}
+
+static int memcg_parent_account(struct mem_cgroup *memcg, void *data)
+{
+ if (memcg == data)
+ return 0;
+
+ set_bit(KMEM_ACCOUNTED_PARENT, &memcg->kmem_accounted);
+ return 0;
+}
+
+static int memcg_parent_no_account(struct mem_cgroup *memcg, void *data)
+{
+ if (memcg == data)
+ return 0;
+
+ clear_bit(KMEM_ACCOUNTED_PARENT, &memcg->kmem_accounted);
+ /*
+ * Stop propagation if we are accounted: our children should
+ * be parent-accounted
+ */
+ return test_bit(KMEM_ACCOUNTED_THIS, &memcg->kmem_accounted);
+}
+
+static void mem_cgroup_update_kmem_limit(struct mem_cgroup *memcg, u64 val)
+{
+ mutex_lock(&set_limit_mutex);
+ if (!test_and_set_bit(KMEM_ACCOUNTED_THIS, &memcg->kmem_accounted) &&
+ val != RESOURCE_MAX) {
+
+ /*
+ * Once enabled, can't be disabled. We could in theory
+ * disable it if we haven't yet created any caches, or
+ * if we can shrink them all to death.
+ *
+ * But it is not worth the trouble
+ */
+ static_key_slow_inc(&mem_cgroup_kmem_enabled_key);
+
+ rcu_read_lock();
+ walk_tree_from(memcg, memcg_parent_account, memcg_nop, memcg);
+ rcu_read_unlock();
+ } else if (test_and_clear_bit(KMEM_ACCOUNTED_THIS, &memcg->kmem_accounted)
+ && val == RESOURCE_MAX) {
+
+ rcu_read_lock();
+ walk_tree_from(memcg, memcg_parent_no_account,
+ memcg_nop, memcg);
+ rcu_read_unlock();
+ }
+
+ mutex_unlock(&set_limit_mutex);
+}
+#endif
/*
* The user of this function is...
* RES_LIMIT.
@@ -4509,20 +4623,8 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
ret = res_counter_set_limit(&memcg->kmem, val);
if (ret)
break;
- /*
- * Once enabled, can't be disabled. We could in theory
- * disable it if we haven't yet created any caches, or
- * if we can shrink them all to death.
- *
- * But it is not worth the trouble
- */
- mutex_lock(&set_limit_mutex);
- if (!memcg->kmem_accounted && val != RESOURCE_MAX
- && !memcg->kmem_accounted) {
- static_key_slow_inc(&mem_cgroup_kmem_enabled_key);
- memcg->kmem_accounted = true;
- }
- mutex_unlock(&set_limit_mutex);
+ mem_cgroup_update_kmem_limit(memcg, val);
+ break;
}
#endif
else
@@ -5592,6 +5694,8 @@ err_cleanup:
}
+static DEFINE_MUTEX(memcg_list_mutex);
+
static struct cgroup_subsys_state * __ref
mem_cgroup_create(struct cgroup *cont)
{
@@ -5607,6 +5711,7 @@ mem_cgroup_create(struct cgroup *cont)
if (alloc_mem_cgroup_per_zone_info(memcg, node))
goto free_out;
+ INIT_LIST_HEAD(&memcg->children);
/* root ? */
if (cont->parent == NULL) {
int cpu;
@@ -5645,6 +5750,10 @@ mem_cgroup_create(struct cgroup *cont)
* mem_cgroup(see mem_cgroup_put).
*/
mem_cgroup_get(parent);
+
+ mutex_lock(&memcg_list_mutex);
+ list_add_rcu(&memcg->siblings, &parent->children);
+ mutex_unlock(&memcg_list_mutex);
} else {
res_counter_init(&memcg->res, NULL);
res_counter_init(&memcg->memsw, NULL);
@@ -5687,9 +5796,15 @@ static int mem_cgroup_pre_destroy(struct cgroup *cont)
static void mem_cgroup_destroy(struct cgroup *cont)
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+ struct mem_cgroup *parent = parent_mem_cgroup(memcg);
kmem_cgroup_destroy(memcg);
+ mutex_lock(&memcg_list_mutex);
+ if (parent)
+ list_del_rcu(&memcg->siblings);
+ mutex_unlock(&memcg_list_mutex);
+
mem_cgroup_put(memcg);
}
--
1.7.7.6
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| Re: [PATCH v3 00/28] kmem limitation for memcg [message #46550 is a reply to message #46544] |
Mon, 28 May 2012 08:32 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
On 05/25/2012 06:34 PM, Christoph Lameter wrote:
> On Fri, 25 May 2012, Michal Hocko wrote:
>
>> On Fri 25-05-12 17:03:20, Glauber Costa wrote:
>>> I believe some of the early patches here are already in some trees around.
>>> I don't know who should pick this, so if everyone agrees with what's in here,
>>> please just ack them and tell me which tree I should aim for (-mm? Hocko's?)
>>> and I'll rebase it.
>>
>> memcg-devel tree is only to make development easier. Everything that
>> applies on top of this tree should be applicable to both -mm and
>> linux-next.
>> So the patches should go via traditional Andrew's channel.
>
> It would be best to merge these with my patchset to extract common code
> from the allocators. The modifications of individual slab allocators would
> then be not necessary anymore and it would save us a lot of work.
>
Some of them would not, some of them would still be. But also please
note that the patches here that deal with differences between allocators
are usually the low hanging fruits compared to the rest.
I agree that long term it not only better, but inevitable, if we are
going to merge both.
But right now, I think we should agree with the implementation itself -
so if you have any comments on how I am handling these, I'd be happy to
hear. Then we can probably set up a tree that does both, or get your
patches merged and I'll rebase, etc.
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| Re: [PATCH v3 12/28] slab: pass memcg parameter to kmem_cache_create [message #46564 is a reply to message #46533] |
Tue, 29 May 2012 14:27 |
Christoph Lameter
Messages: 123
Registered: September 2006
|
Senior Member |
|
|
On Fri, 25 May 2012, Glauber Costa wrote:
> index 06e4a3e..7c0cdd6 100644
> --- a/include/linux/slab_def.h
> +++ b/include/linux/slab_def.h
> @@ -102,6 +102,13 @@ struct kmem_cache {
> */
> };
>
> +static inline void store_orig_align(struct kmem_cache *cachep, int orig_align)
> +{
> +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
> + cachep->memcg_params.orig_align = orig_align;
> +#endif
> +}
> +
Why do you need to store the original alignment? Is the calculated
alignment not enough?
> +++ b/mm/slab.c
> @@ -1729,6 +1729,31 @@ void __init kmem_cache_init_late(void)
> */
> }
>
> +static int __init memcg_slab_register_all(void)
> +{
> +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
> + struct kmem_cache *cachep;
> + struct cache_sizes *sizes;
> +
> + sizes = malloc_sizes;
> +
> + while (sizes->cs_size != ULONG_MAX) {
> + if (sizes->cs_cachep)
> + mem_cgroup_register_cache(NULL, sizes->cs_cachep);
> + if (sizes->cs_dmacachep)
> + mem_cgroup_register_cache(NULL, sizes->cs_dmacachep);
> + sizes++;
> + }
> +
> + mutex_lock(&cache_chain_mutex);
> + list_for_each_entry(cachep, &cache_chain, next)
> + mem_cgroup_register_cache(NULL, cachep);
> +
> + mutex_unlock(&cache_chain_mutex);
> +#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
> + return 0;
> +}
Ok this only duplicates the kmalloc arrays. Why not the others?
> @@ -2331,7 +2350,7 @@ kmem_cache_create (const char *name, size_t size, size_t align,
> continue;
> }
>
> - if (!strcmp(pc->name, name)) {
> + if (!memcg && !strcmp(pc->name, name)) {
> printk(KERN_ERR
> "kmem_cache_create: duplicate cache %s\n", name);
> dump_stack();
This implementation means that duplicate cache detection will no longer
work within a cgroup?
> @@ -2543,7 +2564,12 @@ kmem_cache_create (const char *name, size_t size, size_t align,
> cachep->ctor = ctor;
> cachep->name = name;
>
> + if (g_cpucache_up >= FULL)
> + mem_cgroup_register_cache(memcg, cachep);
What happens if a cgroup was active during creation of slab xxy but
then a process running in a different cgroup uses that slab to allocate
memory? Is it charged to the first cgroup?
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| Re: [PATCH v3 13/28] slub: create duplicate cache [message #46565 is a reply to message #46537] |
Tue, 29 May 2012 14:36 |
Christoph Lameter
Messages: 123
Registered: September 2006
|
Senior Member |
|
|
On Fri, 25 May 2012, Glauber Costa wrote:
> index dacd1fb..4689034 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -467,6 +467,23 @@ struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
> EXPORT_SYMBOL(tcp_proto_cgroup);
> #endif /* CONFIG_INET */
>
> +char *mem_cgroup_cache_name(struct mem_cgroup *memcg, struct kmem_cache *cachep)
> +{
> + char *name;
> + struct dentry *dentry;
> +
> + rcu_read_lock();
> + dentry = rcu_dereference(memcg->css.cgroup->dentry);
> + rcu_read_unlock();
> +
> + BUG_ON(dentry == NULL);
> +
> + name = kasprintf(GFP_KERNEL, "%s(%d:%s)",
> + cachep->name, css_id(&memcg->css), dentry->d_name.name);
> +
> + return name;
> +}
Function allocates a string that is supposed to be disposed of by the
caller. That needs to be documented and maybe even the name needs to
reflect that.
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -4002,6 +4002,38 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size,
> }
> EXPORT_SYMBOL(kmem_cache_create);
>
> +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
> +struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
> + struct kmem_cache *s)
> +{
> + char *name;
> + struct kmem_cache *new;
> +
> + name = mem_cgroup_cache_name(memcg, s);
> + if (!name)
> + return NULL;
> +
> + new = kmem_cache_create_memcg(memcg, name, s->objsize, s->align,
> + (s->allocflags & ~SLAB_PANIC), s->ctor);
Hmmm... A full duplicate of the slab cache? We may have many sparsely
used portions of the per node and per cpu structure as a result.
> + * prevent it from being deleted. If kmem_cache_destroy() is
> + * called for the root cache before we call it for a child cache,
> + * it will be queued for destruction when we finally drop the
> + * reference on the child cache.
> + */
> + if (new) {
> + down_write(&slub_lock);
> + s->refcount++;
> + up_write(&slub_lock);
> + }
Why do you need to increase the refcount? You made a full copy right?
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| Re: [PATCH v3 15/28] slub: always get the cache from its page in kfree [message #46566 is a reply to message #46535] |
Tue, 29 May 2012 14:42 |
Christoph Lameter
Messages: 123
Registered: September 2006
|
Senior Member |
|
|
On Fri, 25 May 2012, Glauber Costa wrote:
> struct page already have this information. If we start chaining
> caches, this information will always be more trustworthy than
> whatever is passed into the function
Yes but the lookup of the page struct also costs some cycles. SLAB in
!NUMA mode and SLOB avoid these lookups and can improve their freeing
speed because of that.
> diff --git a/mm/slub.c b/mm/slub.c
> index 0eb9e72..640872f 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -2598,10 +2598,14 @@ redo:
> void kmem_cache_free(struct kmem_cache *s, void *x)
> {
> struct page *page;
> + bool slab_match;
>
> page = virt_to_head_page(x);
>
> - slab_free(s, page, x, _RET_IP_);
> + slab_match = (page->slab == s) | slab_is_parent(page->slab, s);
> + VM_BUG_ON(!slab_match);
Why add a slab_match bool if you do not really need it?
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| Re: [PATCH v3 00/28] kmem limitation for memcg [message #46570 is a reply to message #46550] |
Tue, 29 May 2012 15:07 |
Christoph Lameter
Messages: 123
Registered: September 2006
|
Senior Member |
|
|
On Mon, 28 May 2012, Glauber Costa wrote:
> > It would be best to merge these with my patchset to extract common code
> > from the allocators. The modifications of individual slab allocators would
> > then be not necessary anymore and it would save us a lot of work.
> >
> Some of them would not, some of them would still be. But also please note that
> the patches here that deal with differences between allocators are usually the
> low hanging fruits compared to the rest.
>
> I agree that long term it not only better, but inevitable, if we are going to
> merge both.
>
> But right now, I think we should agree with the implementation itself - so if
> you have any comments on how I am handling these, I'd be happy to hear. Then
> we can probably set up a tree that does both, or get your patches merged and
> I'll rebase, etc.
Just looked over the patchset and its quite intrusive. I have never been
fond of cgroups (IMHO hardware needs to be partitioned at physical
boundaries) so I have not too much insight into what is going on in that
area.
The idea to just duplicate the caches leads to some weird stuff like the
refcounting and the recovery of the arguments used during slab creation.
I think it may be simplest to only account for the pages used by a slab in
a memcg. That code could be added to the functions in the slab allocators
that interface with the page allocators. Those are not that performance
critical and would do not much harm.
If you need per object accounting then the cleanest solution would be to
duplicate the per node arrays per memcg (or only the statistics) and have
the kmem_cache structure only once in memory.
Its best if information is only in one place for design and for performance.
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| Re: [PATCH v3 00/28] kmem limitation for memcg [message #46571 is a reply to message #46570] |
Tue, 29 May 2012 15:44 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
On 05/29/2012 07:07 PM, Christoph Lameter wrote:
> On Mon, 28 May 2012, Glauber Costa wrote:
>
>>> It would be best to merge these with my patchset to extract common code
>>> from the allocators. The modifications of individual slab allocators would
>>> then be not necessary anymore and it would save us a lot of work.
>>>
>> Some of them would not, some of them would still be. But also please note that
>> the patches here that deal with differences between allocators are usually the
>> low hanging fruits compared to the rest.
>>
>> I agree that long term it not only better, but inevitable, if we are going to
>> merge both.
>>
>> But right now, I think we should agree with the implementation itself - so if
>> you have any comments on how I am handling these, I'd be happy to hear. Then
>> we can probably set up a tree that does both, or get your patches merged and
>> I'll rebase, etc.
>
> Just looked over the patchset and its quite intrusive.
Thank you very much, Christoph, appreciate it.
> I have never been
> fond of cgroups (IMHO hardware needs to be partitioned at physical
> boundaries) so I have not too much insight into what is going on in that
> area.
There is certainly a big market for that, and certainly a big market for
what we're doing as well. So there are users interested in Containers
technology, and I don't really see it as "partitioning it here" vs
"partitioning there". It's just different.
Moreover, not everyone doing cgroups are doing containers. Some people
are isolating a service, or a paticular job.
I agree it is an intrusive change, but it used to be even more. I did my
best to diminish its large spread.
> The idea to just duplicate the caches leads to some weird stuff like the
> refcounting and the recovery of the arguments used during slab creation.
The refcounting is only needed so we are sure the parent cache won't go
away without the child caches going away. I can try to find a better way
to do that, specifically.
>
> I think it may be simplest to only account for the pages used by a slab in
> a memcg. That code could be added to the functions in the slab allocators
> that interface with the page allocators. Those are not that performance
> critical and would do not much harm.
No, I don't think so. Well, accounting the page is easy, but when we do
a new allocation, we need to match a process to its correspondent page.
This will likely lead to flushing the internal cpu caches of the slub,
for instance, hurting performance. That is because once we allocate a
page, all objects on that page need to belong to the same cgroup.
Also, you talk about intrusiveness, accounting pages is a lot more
intrusive, since then you need to know a lot about the internal
structure of each cache. Having the cache replicated has exactly the
effect of isolating it better.
I of course agree this is no walk in the park, but accounting something
that is internal to the cache, and that each cache will use and organize
in its own private way, doesn't make it any better.
> If you need per object accounting then the cleanest solution would be to
> duplicate the per node arrays per memcg (or only the statistics) and have
> the kmem_cache structure only once in memory.
No, it's all per-page. Nothing here is per-object, maybe you
misunderstood something?
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| Re: [PATCH v3 12/28] slab: pass memcg parameter to kmem_cache_create [message #46573 is a reply to message #46564] |
Tue, 29 May 2012 15:50 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
On 05/29/2012 06:27 PM, Christoph Lameter wrote:
> On Fri, 25 May 2012, Glauber Costa wrote:
>
>> index 06e4a3e..7c0cdd6 100644
>> --- a/include/linux/slab_def.h
>> +++ b/include/linux/slab_def.h
>> @@ -102,6 +102,13 @@ struct kmem_cache {
>> */
>> };
>>
>> +static inline void store_orig_align(struct kmem_cache *cachep, int orig_align)
>> +{
>> +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
>> + cachep->memcg_params.orig_align = orig_align;
>> +#endif
>> +}
>> +
>
> Why do you need to store the original alignment? Is the calculated
> alignment not enough?
I think this one can go. You are right.
>> +++ b/mm/slab.c
>> @@ -1729,6 +1729,31 @@ void __init kmem_cache_init_late(void)
>> */
>> }
>>
>> +static int __init memcg_slab_register_all(void)
>> +{
>> +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
>> + struct kmem_cache *cachep;
>> + struct cache_sizes *sizes;
>> +
>> + sizes = malloc_sizes;
>> +
>> + while (sizes->cs_size != ULONG_MAX) {
>> + if (sizes->cs_cachep)
>> + mem_cgroup_register_cache(NULL, sizes->cs_cachep);
>> + if (sizes->cs_dmacachep)
>> + mem_cgroup_register_cache(NULL, sizes->cs_dmacachep);
>> + sizes++;
>> + }
>> +
>> + mutex_lock(&cache_chain_mutex);
>> + list_for_each_entry(cachep,&cache_chain, next)
>> + mem_cgroup_register_cache(NULL, cachep);
>> +
>> + mutex_unlock(&cache_chain_mutex);
>> +#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
>> + return 0;
>> +}
>
> Ok this only duplicates the kmalloc arrays. Why not the others?
It does duplicate the others.
First it does a while look on the kmalloc caches, then a
list_for_each_entry in the rest. You probably missed it.
>> @@ -2331,7 +2350,7 @@ kmem_cache_create (const char *name, size_t size, size_t align,
>> continue;
>> }
>>
>> - if (!strcmp(pc->name, name)) {
>> + if (!memcg&& !strcmp(pc->name, name)) {
>> printk(KERN_ERR
>> "kmem_cache_create: duplicate cache %s\n", name);
>> dump_stack();
>
> This implementation means that duplicate cache detection will no longer
> work within a cgroup?
For the slab, yes. For the slub, I check to see if they belong to the
same memcg.
That said, this can and should be fixed here too, thanks for spotting.
>> @@ -2543,7 +2564,12 @@ kmem_cache_create (const char *name, size_t size, size_t align,
>> cachep->ctor = ctor;
>> cachep->name = name;
>>
>> + if (g_cpucache_up>= FULL)
>> + mem_cgroup_register_cache(memcg, cachep);
>
> What happens if a cgroup was active during creation of slab xxy but
> then a process running in a different cgroup uses that slab to allocate
> memory? Is it charged to the first cgroup?
I don't see this situation ever happening. kmem_cache_create, when
called directly, will always create a global cache. It doesn't matter
which cgroups are or aren't active at this time or any other. We create
copies per-cgroup, but we create it lazily, when someone will touch it.
At that point, which cache will be used depend on which process is using
it.
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| Re: [PATCH v3 13/28] slub: create duplicate cache [message #46574 is a reply to message #46565] |
Tue, 29 May 2012 15:56 |
Glauber Costa
Messages: 916
Registered: October 2011
|
Senior Member |
|
|
On 05/29/2012 06:36 PM, Christoph Lameter wrote:
> On Fri, 25 May 2012, Glauber Costa wrote:
>
>> index dacd1fb..4689034 100644
>> --- a/mm/memcontrol.c
>> +++ b/mm/memcontrol.c
>> @@ -467,6 +467,23 @@ struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
>> EXPORT_SYMBOL(tcp_proto_cgroup);
>> #endif /* CONFIG_INET */
>>
>> +char *mem_cgroup_cache_name(struct mem_cgroup *memcg, struct kmem_cache *cachep)
>> +{
>> + char *name;
>> + struct dentry *dentry;
>> +
>> + rcu_read_lock();
>> + dentry = rcu_dereference(memcg->css.cgroup->dentry);
>> + rcu_read_unlock();
>> +
>> + BUG_ON(dentry == NULL);
>> +
>> + name = kasprintf(GFP_KERNEL, "%s(%d:%s)",
>> + cachep->name, css_id(&memcg->css), dentry->d_name.name);
>> +
>> + return name;
>> +}
>
> Function allocates a string that is supposed to be disposed of by the
> caller. That needs to be documented and maybe even the name needs to
> reflect that.
Okay, I can change it.
>> --- a/mm/slub.c
>> +++ b/mm/slub.c
>> @@ -4002,6 +4002,38 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size,
>> }
>> EXPORT_SYMBOL(kmem_cache_create);
>>
>> +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
>> +struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
>> + struct kmem_cache *s)
>> +{
>> + char *name;
>> + struct kmem_cache *new;
>> +
>> + name = mem_cgroup_cache_name(memcg, s);
>> + if (!name)
>> + return NULL;
>> +
>> + new = kmem_cache_create_memcg(memcg, name, s->objsize, s->align,
>> + (s->allocflags& ~SLAB_PANIC), s->ctor);
>
> Hmmm... A full duplicate of the slab cache? We may have many sparsely
> used portions of the per node and per cpu structure as a result.
I've already commented on patch 0, but I will repeat it here. This
approach leads to more fragmentation, yes, but this is exactly to be
less intrusive.
With a full copy, all I need to do is:
1) relay the allocation to the right cache.
2) account for a new page when it is needed.
How does the cache work from inside? I don't care.
Accounting pages seems just crazy to me. If new allocators come in the
future, organizing the pages in a different way, instead of patching it
here and there, we need to totally rewrite this.
If those allocators happen to depend on a specific placement for
performance, then we're destroying this as well too.
>
>> + * prevent it from being deleted. If kmem_cache_destroy() is
>> + * called for the root cache before we call it for a child cache,
>> + * it will be queued for destruction when we finally drop the
>> + * reference on the child cache.
>> + */
>> + if (new) {
>> + down_write(&slub_lock);
>> + s->refcount++;
>> + up_write(&slub_lock);
>> + }
>
> Why do you need to increase the refcount? You made a full copy right?
Yes, but I don't want this copy to go away while we have other caches
around.
So, in the memcg internals, I used a different reference counter, to
avoid messing with this one. I could use that, and leave the original
refcnt alone. Would you prefer this?
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| Re: [PATCH v3 00/28] kmem limitation for memcg [message #46575 is a reply to message #46571] |
Tue, 29 May 2012 16:01 |
Christoph Lameter
Messages: 123
Registered: September 2006
|
Senior Member |
|
|
On Tue, 29 May 2012, Glauber Costa wrote:
> > I think it may be simplest to only account for the pages used by a slab in
> > a memcg. That code could be added to the functions in the slab allocators
> > that interface with the page allocators. Those are not that performance
> > critical and would do not much harm.
>
> No, I don't think so. Well, accounting the page is easy, but when we do a new
> allocation, we need to match a process to its correspondent page. This will
> likely lead to flushing the internal cpu caches of the slub, for instance,
> hurting performance. That is because once we allocate a page, all objects on
> that page need to belong to the same cgroup.
Matching a process to its page is a complex thing even for pages used by
userspace.
How can you make sure that all objects on a page belong to the same
cgroup? There are various kernel allocations that have uses far beyond a
single context. There is already a certain degree of fuzziness there and
we tolerate that in other contexts as well.
> Also, you talk about intrusiveness, accounting pages is a lot more intrusive,
> since then you need to know a lot about the internal structure of each cache.
> Having the cache replicated has exactly the effect of isolating it better.
Why would you need to know about the internal structure? Just get the
current process context and use the cgroup that is readily available there
to account for the pages.
> > If you need per object accounting then the cleanest solution would be to
> > duplicate the per node arrays per memcg (or only the statistics) and have
> > the kmem_cache structure only once in memory.
>
> No, it's all per-page. Nothing here is per-object, maybe you misunderstood
> something?
There are free/used object counters in each page. You could account for
objects in the l3 lists or kmem_cache_node strcut and thereby avoid
having to deal with the individual objects at the per cpu level.
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