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| author | Johannes Weiner <hannes@cmpxchg.org> | 2016-01-21 00:03:16 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-21 02:09:18 +0100 |
| commit | 44b7a8d33d666268062e0f725d5f14813a63a6ea (patch) | |
| tree | 976a8ef6d69e8d34be1b07ec5f5d75e26b291ceb /Documentation | |
| parent | Documentation: cgroup: add memory.swap.{current,max} description (diff) | |
| download | linux-44b7a8d33d666268062e0f725d5f14813a63a6ea.tar.xz linux-44b7a8d33d666268062e0f725d5f14813a63a6ea.zip | |
mm: memcontrol: do not uncharge old page in page cache replacement
Changing page->mem_cgroup of a live page is tricky and fragile. In
particular, the memcg writeback code relies on that mapping being stable
and users of mem_cgroup_replace_page() not overlapping with dirtyable
inodes.
Page cache replacement doesn't have to do that, though. Instead of being
clever and transferring the charge from the old page to the new,
force-charge the new page and leave the old page alone. A temporary
overcharge won't matter in practice, and the old page is going to be freed
shortly after this anyway. And this is not performance critical.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
0 files changed, 0 insertions, 0 deletions