| [PATCH v5 0/2] fix static_key disabling problem in memcg [message #46346] |
Fri, 11 May 2012 20:11  |
Glauber Costa
Messages: 916
Registered: October 2011
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Senior Member |
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Hi, Tejun, Kame,
This series is composed of the two patches of the last fix, with no changes
(only exception is the removal of x = false assignments that Tejun requested,
that is done now). Note also that patch 1 of this series was reused by me
in the slab accounting patches for memcg.
The first patch, that adds a mutex to memcg is dropped. I didn't posted it
before so I could wait for Kame to get back from his vacations and properly
review it.
Kame: Steven Rostedt pointed out that our analysis of the static branch updates
were wrong, so the mutex is really not needed.
The key to understand that, is that atomic_inc_not_zero will only return right
away if the value is not yet zero - as the name implies - but the update in the
atomic variable only happens after the code is patched.
Therefore, if two callers enters with a key value of zero, both will be held at
the jump_label_lock() call, effectively guaranteeing the behavior we need.
Glauber Costa (2):
Always free struct memcg through schedule_work()
decrement static keys on real destroy time
include/net/sock.h | 9 ++++++++
mm/memcontrol.c | 50 +++++++++++++++++++++++++++++++++-----------
net/ipv4/tcp_memcontrol.c | 32 ++++++++++++++++++++++------
3 files changed, 71 insertions(+), 20 deletions(-)
--
1.7.7.6
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