From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:36680) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TGPdW-0001Lp-58 for qemu-devel@nongnu.org; Tue, 25 Sep 2012 03:32:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TGPdV-0006NK-7a for qemu-devel@nongnu.org; Tue, 25 Sep 2012 03:32:54 -0400 Received: from lgemrelse6q.lge.com ([156.147.1.121]:59865) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TGPdU-0006N4-Sf for qemu-devel@nongnu.org; Tue, 25 Sep 2012 03:32:53 -0400 Date: Tue, 25 Sep 2012 16:35:57 +0900 From: Minchan Kim Message-ID: <20120925073557.GM13234@bbox> References: <1348224383-1499-1-git-send-email-mgorman@suse.de> <1348224383-1499-7-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1348224383-1499-7-git-send-email-mgorman@suse.de> Subject: Re: [Qemu-devel] [PATCH 6/9] mm: compaction: Acquire the zone->lock as late as possible List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mel Gorman Cc: Richard Davies , KVM , QEMU-devel , LKML , Linux-MM , Avi Kivity , Andrew Morton , Shaohua Li On Fri, Sep 21, 2012 at 11:46:20AM +0100, Mel Gorman wrote: > Compactions free scanner acquires the zone->lock when checking for PageBuddy > pages and isolating them. It does this even if there are no PageBuddy pages > in the range. > > This patch defers acquiring the zone lock for as long as possible. In the > event there are no free pages in the pageblock then the lock will not be > acquired at all which reduces contention on zone->lock. > > Signed-off-by: Mel Gorman > Acked-by: Rik van Riel Acked-by: Minchan Kim -- Kind regards, Minchan Kim