diff options
| author | Yang Shi <yang.shi@linux.alibaba.com> | 2020-04-01 21:06:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-02 09:35:28 -0700 |
| commit | 9a9b6cce630d14851ab09534b6462258486048cd (patch) | |
| tree | 951326bab4333b0a3328e0f5f510de8d7e27b903 /kernel/user_namespace.c | |
| parent | 1eb6234e52f0cbb87f59c328687127866d57941a (diff) | |
mm: swap: use smp_mb__after_atomic() to order LRU bit set
Memory barrier is needed after setting LRU bit, but smp_mb() is too
strong. Some architectures, i.e. x86, imply memory barrier with atomic
operations, so replacing it with smp_mb__after_atomic() sounds better,
which is nop on strong ordered machines, and full memory barriers on
others. With this change the vm-scalability cases would perform better on
x86, I saw total 6% improvement with this patch and previous inline fix.
The test data (lru-file-readtwice throughput) against v5.6-rc4:
mainline w/ inline fix w/ both (adding this)
150MB 154MB 159MB
Fixes: 9c4e6b1a7027 ("mm, mlock, vmscan: no more skipping pagevecs")
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: http://lkml.kernel.org/r/1584500541-46817-2-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/user_namespace.c')
0 files changed, 0 insertions, 0 deletions