diff options
author | Cody P Schafer <cody@linux.vnet.ibm.com> | 2013-07-03 18:01:31 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-03 19:07:27 -0400 |
commit | 8d7a8fa97abeb4fd6b3975d32c9f859875157770 (patch) | |
tree | 99e057e6b90bd514e645ed0539d1d1b8178046d3 /fs/select.c | |
parent | c8e251fadc6220261f6e0c6b8a4f1cdf27626165 (diff) |
mm/page_alloc: insert memory barriers to allow async update of pcp batch and high
Introduce pageset_update() to perform a safe transision from one set of
pcp->{batch,high} to a new set using memory barriers.
This ensures that batch is always set to a safe value (1) prior to
updating high, and ensure that high is fully updated before setting the
real value of batch. It avoids ->batch ever rising above ->high.
Suggested by Gilad Ben-Yossef in these threads:
https://lkml.org/lkml/2013/4/9/23
https://lkml.org/lkml/2013/4/10/49
Also reproduces his proposed comment.
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Reviewed-by: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/select.c')
0 files changed, 0 insertions, 0 deletions