From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43197) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1coClb-00052F-B6 for qemu-devel@nongnu.org; Wed, 15 Mar 2017 13:31:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1coCla-0003ep-F0 for qemu-devel@nongnu.org; Wed, 15 Mar 2017 13:31:19 -0400 Date: Wed, 15 Mar 2017 17:31:09 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20170315173108.GB2701@work-vm> References: <1489549053-31728-1-git-send-email-jemmy858585@gmail.com> <20170315111021.GD3088@lemon.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170315111021.GD3088@lemon.lan> 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: Fam Zheng Cc: Lidong Chen , qemu-devel@nongnu.org, stefanha@redhat.com, quintela@redhat.com, qemu-block@nongnu.org * Fam Zheng (famz@redhat.com) wrote: > 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 Are you taking that via a block pull? Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK