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| author |   Johannes Weiner <hannes@cmpxchg.org> | 2014-08-06 16:06:01 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-06 18:01:17 -0700 |
| commit | 9a2385eef9f28fb5260c48c45fc8fe01f1da70a6 (patch) | |
| tree | 1bd5538a1901519316b5b59f73dbf3ed508a8501 /drivers/base/memory.c | |
| parent | mm: memcontrol: use root_mem_cgroup res_counter (diff) | |
| download | linux-dev-9a2385eef9f28fb5260c48c45fc8fe01f1da70a6.tar.xz linux-dev-9a2385eef9f28fb5260c48c45fc8fe01f1da70a6.zip | |
mm: memcontrol: remove ordering between pc->mem_cgroup and PageCgroupUsed
There is a write barrier between setting pc->mem_cgroup and
PageCgroupUsed, which was added to allow LRU operations to lookup the
memcg LRU list of a page without acquiring the page_cgroup lock.
But ever since commit 38c5d72f3ebe ("memcg: simplify LRU handling by new
rule"), pages are ensured to be off-LRU while charging, so nobody else
is changing LRU state while pc->mem_cgroup is being written, and there
are no read barriers anymore.
Remove the unnecessary write barrier.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/base/memory.c')
0 files changed, 0 insertions, 0 deletions