Messages in this thread | | | Date | Fri, 25 Jul 2014 13:34:13 +0100 | From | Mel Gorman <> | Subject | Re: [PATCH V4 09/15] mm, compaction: skip rechecks when lock was already held |
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On Wed, Jul 16, 2014 at 03:48:17PM +0200, Vlastimil Babka wrote: > Compaction scanners try to lock zone locks as late as possible by checking > many page or pageblock properties opportunistically without lock and skipping > them if not unsuitable. For pages that pass the initial checks, some properties > have to be checked again safely under lock. However, if the lock was already > held from a previous iteration in the initial checks, the rechecks are > unnecessary. > > This patch therefore skips the rechecks when the lock was already held. This is > now possible to do, since we don't (potentially) drop and reacquire the lock > between the initial checks and the safe rechecks anymore. > > Signed-off-by: Vlastimil Babka <vbabka@suse.cz> > Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> > Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> > Acked-by: Minchan Kim <minchan@kernel.org> > Cc: Mel Gorman <mgorman@suse.de> > Cc: Michal Nazarewicz <mina86@mina86.com> > Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> > Cc: Christoph Lameter <cl@linux.com> > Cc: Rik van Riel <riel@redhat.com> > Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
-- Mel Gorman SUSE Labs
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