From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55071) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1co6p4-0006ol-Q9 for qemu-devel@nongnu.org; Wed, 15 Mar 2017 07:10:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1co6p3-0004wA-VE for qemu-devel@nongnu.org; Wed, 15 Mar 2017 07:10:30 -0400 Date: Wed, 15 Mar 2017 19:10:21 +0800 From: Fam Zheng Message-ID: <20170315111021.GD3088@lemon.lan> References: <1489549053-31728-1-git-send-email-jemmy858585@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1489549053-31728-1-git-send-email-jemmy858585@gmail.com> Subject: Re: [Qemu-devel] [PATCH v2] migration/block: Avoid invoking blk_drain too frequently List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Lidong Chen Cc: qemu-devel@nongnu.org, stefanha@redhat.com, quintela@redhat.com, dgilbert@redhat.com, qemu-block@nongnu.org On Wed, 03/15 11:37, Lidong Chen wrote: > Increase bmds->cur_dirty after submit io, so reduce the frequency > involve into blk_drain, and improve the performance obviously > when block migration. > > The performance test result of this patch: > > During the block dirty save phase, this patch improve guest os IOPS > from 4.0K to 9.5K. and improve the migration speed from > 505856 rsec/s to 855756 rsec/s. > > Signed-off-by: Lidong Chen > --- > migration/block.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/migration/block.c b/migration/block.c > index 6741228..7734ff7 100644 > --- a/migration/block.c > +++ b/migration/block.c > @@ -576,6 +576,9 @@ static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds, > } > > bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, sector, nr_sectors); > + sector += nr_sectors; > + bmds->cur_dirty = sector; > + > break; > } > sector += BDRV_SECTORS_PER_DIRTY_CHUNK; > -- > 1.8.3.1 > Nice catch above all, thank you! Reviewed-by: Fam Zheng