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| author | Johannes Weiner <hannes@cmpxchg.org> | 2016-03-15 14:57:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-15 16:55:16 -0700 |
| commit | fdf1cdb91b6ab7a8a91df68c384f36b8a0909cab (patch) | |
| tree | 828ad38946acad9990dcc733a10ebdeed0c1fbd5 /mm/truncate.c | |
| parent | 62cccb8c8e7a3ca233f49d5e7dcb1557d25465cd (diff) | |
| download | lwn-fdf1cdb91b6ab7a8a91df68c384f36b8a0909cab.tar.gz lwn-fdf1cdb91b6ab7a8a91df68c384f36b8a0909cab.zip | |
mm: remove unnecessary uses of lock_page_memcg()
There are several users that nest lock_page_memcg() inside lock_page()
to prevent page->mem_cgroup from changing. But the page lock prevents
pages from moving between cgroups, so that is unnecessary overhead.
Remove lock_page_memcg() in contexts with locked contexts and fix the
debug code in the page stat functions to be okay with the page lock.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/truncate.c')
| -rw-r--r-- | mm/truncate.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/mm/truncate.c b/mm/truncate.c index 87311af936f2..7598b552ae03 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -527,7 +527,6 @@ invalidate_complete_page2(struct address_space *mapping, struct page *page) if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) return 0; - lock_page_memcg(page); spin_lock_irqsave(&mapping->tree_lock, flags); if (PageDirty(page)) goto failed; @@ -535,7 +534,6 @@ invalidate_complete_page2(struct address_space *mapping, struct page *page) BUG_ON(page_has_private(page)); __delete_from_page_cache(page, NULL); spin_unlock_irqrestore(&mapping->tree_lock, flags); - unlock_page_memcg(page); if (mapping->a_ops->freepage) mapping->a_ops->freepage(page); @@ -544,7 +542,6 @@ invalidate_complete_page2(struct address_space *mapping, struct page *page) return 1; failed: spin_unlock_irqrestore(&mapping->tree_lock, flags); - unlock_page_memcg(page); return 0; } |