OpenVZ Forum


Home » Mailing lists » Devel » BC: resource beancounters (v6) (with userpages reclamation + configfs)
[PATCH 10/13] BC: physpages accounting (core) [message #8170 is a reply to message #8159] Thu, 09 November 2006 16:59 Go to previous messageGo to previous message
dev is currently offline  dev
Messages: 1693
Registered: September 2005
Location: Moscow
Senior Member
This is the core of vmrss accounting.

The main introduced object is page_beancounter.
It ties together page and BCs which use the page.
page_beancounter also allows quick per-container pages reclamation.
and helps correctly account fractions of memory shared
between BCs (http://wiki.openvz.org/RSS_fractions_accounting)

Page charge/uncharge is performed on first map/last unmap
and is based on page->mapcount calculations.

Signed-Off-By: Pavel Emelianov <xemul@sw.ru>
Signed-Off-By: Kirill Korotaev <dev@sw.ru>

---

include/bc/beancounter.h | 2
include/bc/rsspages.h | 46 ++++++++
include/linux/mm.h | 5
include/linux/mm_types.h | 5
kernel/bc/beancounter.c | 2
kernel/bc/rsspages.c | 267 +++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 326 insertions(+), 1 deletion(-)

--- ./include/bc/beancounter.h.ve9 2006-11-07 12:03:41.000000000 +0300
+++ ./include/bc/beancounter.h 2006-11-07 12:03:47.000000000 +0300
@@ -67,6 +67,8 @@ struct beancounter {
bcid_t bc_id;
struct hlist_node bc_hash;

+ spinlock_t bc_page_lock;
+ struct list_head bc_page_list;
struct bc_resource_parm bc_parms[BC_RESOURCES];
};

--- /dev/null 2006-07-18 14:52:43.075228448 +0400
+++ ./include/bc/rsspages.h 2006-11-07 12:03:57.000000000 +0300
@@ -0,0 +1,46 @@
+/*
+ * include/bc/rsspages.h
+ *
+ * Copyright (C) 2006 OpenVZ SWsoft Inc
+ *
+ */
+
+#ifndef __BC_RSSPAGES_H_
+#define __BC_RSSPAGES_H_
+
+#include <linux/compiler.h>
+
+struct page;
+struct vm_area_struct;
+struct page_beancounter;
+
+#ifdef CONFIG_BEANCOUNTERS
+int __must_check bc_rsspage_prepare(struct page *p,
+ struct vm_area_struct *vma, struct page_beancounter **ppb);
+void bc_rsspage_charge(struct page_beancounter *pb);
+void bc_rsspage_release(struct page_beancounter *pb);
+void bc_rsspage_uncharge(struct page_beancounter *pb);
+
+unsigned long bc_try_to_free_pages(struct beancounter *bc);
+unsigned long bc_isolate_pages(unsigned long nr_to_scan,
+ struct beancounter *bc, struct list_head *dst,
+ int active, unsigned long *scanned);
+unsigned long bc_nr_physpages(struct beancounter *bc);
+#else
+static inline int __must_check bc_rsspage_prepare(struct page *p,
+ struct vm_area_struct *vma, struct page_beancounter **ppb)
+{
+ return 0;
+}
+
+static inline void bc_rsspage_charge(struct page_beancounter *pb)
+{
+}
+static inline void bc_rsspage_release(struct page_beancounter *pb)
+{
+}
+static inline void bc_rsspage_uncharge(struct page_beancounter *pb)
+{
+}
+#endif
+#endif
--- ./include/linux/mm.h.ve9 2006-11-07 12:03:41.000000000 +0300
+++ ./include/linux/mm.h 2006-11-07 12:03:47.000000000 +0300
@@ -223,6 +223,11 @@ struct mmu_gather;
struct inode;

#define page_bc(page) ((page)->bc)
+#ifdef CONFIG_BEANCOUNTERS
+#define page_pb(page) ((page)->pb)
+#else
+#define page_pb(page) (NULL)
+#endif
#define page_private(page) ((page)->private)
#define set_page_private(page, v) ((page)->private = (v))

--- ./include/linux/mm_types.h.ve9 2006-11-07 12:03:41.000000000 +0300
+++ ./include/linux/mm_types.h 2006-11-07 12:03:47.000000000 +0300
@@ -63,7 +63,10 @@ struct page {
not kmapped, ie. highmem) */
#endif /* WANT_PAGE_VIRTUAL */
#ifdef CONFIG_BEANCOUNTERS
- struct beancounter *bc;
+ union {
+ struct beancounter *bc;
+ struct page_beancounter *pb;
+ };
#endif
#ifdef CONFIG_PAGE_OWNER
int order;
--- ./kernel/bc/beancounter.c.ve9 2006-11-07 12:03:41.000000000 +0300
+++ ./kernel/bc/beancounter.c 2006-11-07 12:03:47.000000000 +0300
@@ -227,6 +227,8 @@ void __init bc_init_early(void)
int i;

init_beancounter_struct(&init_bc, 0);
+ spin_lock_init(&init_bc.bc_page_lock);
+ INIT_LIST_HEAD(&init_bc.bc_page_list);

for (i = 0; i < BC_RESOURCES; i++) {
init_bc.bc_parms[i].barrier = BC_MAXVALUE;
--- /dev/null 2006-07-18 14:52:43.075228448 +0400
+++ ./kernel/bc/rsspages.c 2006-11-07 12:03:47.000000000 +0300
@@ -0,0 +1,267 @@
+/*
+ * kernel/bc/rsspages.c
+ *
+ * Copyright (C) 2006 OpenVZ SWsoft Inc
+ *
+ */
+
+#include <linux/mm_types.h>
+#include <linux/mm.h>
+#include <linux/page-flags.h>
+#include <linux/hardirq.h>
+#include <linux/kernel.h>
+
+#include <bc/beancounter.h>
+#include <bc/vmpages.h>
+#include <bc/rsspages.h>
+
+#include <asm/bitops.h>
+
+#define BC_PHYSPAGES_BARRIER BC_MAXVALUE
+#define BC_PHYSPAGES_LIMIT BC_MAXVALUE
+
+/*
+ * page_beancounter is a tie between page and beancounter page is
+ * charged to. it is used to reclaim pages faster by walking bc's
+ * page list, not zones' ones
+ *
+ * this tie can also be used to implement fractions accounting mechanism
+ * as it is done in OpenVZ kernels
+ */
+struct page_beancounter {
+ struct page *page;
+ struct beancounter *bc;
+ struct list_head list;
+};
+
+/*
+ * API calls
+ */
+
+/*
+ * bc_rsspage_prepare allocates a tie and charges page to vma's beancounter
+ * this must be called in non-atomic context to give a chance for pages
+ * reclaiming. otherwise hitting limits will cause -ENOMEM returned.
+ */
+int bc_rsspage_prepare(struct page *page, struct vm_area_struct *vma,
+ struct page_beancounter **ppb)
+{
+ struct beancounter *bc;
+ struct page_beancounter *pb;
+
+ pb = kmalloc(sizeof(struct page_beancounter), GFP_KERNEL);
+ if (pb == NULL)
+ goto out_nomem;
+
+ bc = vma->vma_bc;
+ if (bc_charge(bc, BC_PHYSPAGES, 1, BC_LIMIT))
+ goto out_charge;
+
+ pb->page = page;
+ pb->bc = bc;
+ *ppb = pb;
+ return 0;
+
+out_charge:
+ kfree(pb);
+out_nomem:
+ return -ENOMEM;
+}
+
+/*
+ * bc_rsspage_release is a rollback call for bc_rsspage_prepare
+ */
+void bc_rsspage_release(struct page_beancounter *pb)
+{
+ bc_uncharge(pb->bc, BC_PHYSPAGES, 1);
+ kfree(pb);
+}
+
+/*
+ * bc_rsspage_charge actually ties page and beancounter together
+ * this is done in not-failing path to be sure the page IS charged
+ */
+void bc_rsspage_charge(struct page_beancounter *pb)
+{
+ struct page *pg;
+ struct beancounter *bc;
+
+ pg = pb->page;
+ bc = bc_get(pb->bc);
+
+ spin_lock(&bc->bc_page_lock);
+ list_add(&pb->list, &bc->bc_page_list);
+ spin_unlock(&bc->bc_page_lock);
+
+ page_pb(pg) = pb;
+}
+
+/*
+ * bc_rsspage_uncharge is called when pages is get completely unapped
+ * from all address spaces
+ */
+void bc_rsspage_uncharge(struct page_beancounter *pb)
+{
+ struct page *page;
+ struct beancounter *bc;
+
+ if (pb == NULL)
+ return;
+
+ page = pb->page;
+ bc = pb->bc;
+
+ cmpxchg(&page_pb(page), pb, NULL);
+
+ spin_lock(&bc->bc_page_lock);
+ list_del(&pb->list);
+ spin_unlock(&bc->bc_page_lock);
+
+ bc_uncharge(bc, BC_PHYSPAGES, 1);
+ kfree(pb);
+
+ bc_put(bc);
+}
+
+/*
+ * Page reclamation helper
+ *
+ * this function resembles isolate_lru_pages() but is scans through
+ * bc's page list, not zone's active/inactive ones.
+ */
+
+unsigned long bc_isolate_pages(unsigned long nr_to_scan, struct beancounter *bc,
+ struct list_head *dst, int active, unsigned long *scanned)
+{
+ unsigned long nr_taken = 0;
+ struct page *page;
+ struct page_beancounter *pb;
+ unsigned long scan;
+ struct list_head *src;
+ LIST_HEAD(pb_list);
+ struct zone *z;
+
+ spin_lock(&bc->bc_page_lock);
+ src = &bc->bc_page_list;
+ for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) {
+ struct list_head *target;
+ pb = list_entry(src->prev, struct page_beancounter, list);
+ page = pb->page;
+ z = page_zone(page);
+
+ list_move(&pb->list, &pb_list);
+
+ spin_lock_irq(&z->lru_lock);
+ if (PageLRU(page)) {
+ if ((active && PageActive(page)) ||
+ (!active && !PageActive(page))) {
+ if (likely(get_page_unless_zero(page))) {
+ ClearPageLRU(page);
+ target = dst;
+ nr_taken++;
+ list_move(&page->lru, dst);
+ }
+ }
+ }
+ spin_unlock_irq(&z->lru_lock);
+ }
+
+ list_splice(&pb_list, src);
+ spin_unlock(&bc->bc_page_lock);
+
+ *scanned = scan;
+ return nr_taken;
+}
+
+unsigned long bc_nr_physpages(struct beancounter *bc)
+{
+ return bc->bc_parms[BC_PHYSPAGES].held;
+}
+
+/*
+ * Generic resource info
+ */
+
+static int bc_phys_init(struct beancounter *bc, int res)
+{
+ spin_lock_init(&bc->bc_page_lock);
+ INIT_LIST_HEAD(&bc->bc_page_list);
+
+ bc_init_resource(&bc->bc_parms[BC_PHYSPAGES],
+ BC_PHYSPAGES_BARRIER, BC_PHYSPAGES_LIMIT);
+ return 0;
+}
+
+static void bc_phys_barrier_hit(struct beancounter *bc)
+{
+ /*
+ * May wake up kswapd here to start asynchronous reclaiming of pages
+ */
+}
+
+static int bc_phys_limit_hit(struct beancounter *bc, unsigned long val,
+ unsigned long flags)
+{
+ int did_some_progress = 0;
+ struct bc_resource_parm *parm;
+
+ spin_unlock_irqrestore(&bc->bc_lock, flags);
+ might_sleep();
+
+ parm = &bc->bc_parms[BC_PHYSPAGES];
+ while (1) {
+ did_some_progress = bc_try_to_free_pages(bc);
+
+ spin_lock_irq(&bc->bc_lock);
+ if (parm->held + val <= parm->limit) {
+ parm->held += val;
+ bc_adjust_maxheld(parm);
+ return 0;
+ }
+
+ if (!did_some_progress) {
+ parm->failcnt++;
+ return -ENOMEM;
+ }
+ spin_unlock_irq(&bc->bc_lock);
+ }
+}
+
+static int bc_phys_change(struct beancounter *bc,
+ unsigned long barrier, unsigned long limit)
+{
+ int did_some_progress;
+ struct bc_resource_parm *parm;
+
+ parm = &bc->bc_parms[BC_PHYSPAGES];
+ if (limit >= parm->held)
+ return 0;
+
+ while (1) {
+ spin_unlock_irq(&bc->bc_lock);
+
+ did_some_progress = bc_try_to_free_pages(bc);
+
+ spin_lock_irq(&bc->bc_lock);
+ if (parm->held < limit)
+ return 0;
+ if (!did_some_progress)
+ return -ENOMEM;
+ }
+}
+
+struct bc_resource bc_phys_resource = {
+ .bcr_name = "physpages",
+ .bcr_init = bc_phys_init,
+ .bcr_change = bc_phys_change,
+ .bcr_barrier_hit = bc_phys_barrier_hit,
+ .bcr_limit_hit = bc_phys_limit_hit,
+};
+
+static in ...

[ Show the rest of the message ]

Report message to a moderator

[Message index]
 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: Re: Re: [RFC] [PATCH 0/4] uid_ns: introduction
Next Topic: [PATCH] ext3: small fix for previous retries patch in ext3_prepare_write()
Goto Forum:
  

[ Syndicate this forum (XML) ] [ RSS ] [ PDF ]

Current Time: Mon Sep 08 02:02:12 GMT 2025

Total time taken to generate the page: 0.07566 seconds
Powered by FUDforum Powered by Virtuozzo Containers