lkml.org 
[lkml]   [2014]   [Jul]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH V4 09/15] mm, compaction: skip rechecks when lock was already held
    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


    \
     
     \ /
      Last update: 2014-07-25 15:21    [W:4.104 / U:0.336 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site