From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41661) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1coRIB-0003P0-Mp for qemu-devel@nongnu.org; Thu, 16 Mar 2017 05:01:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1coRI6-00007m-7d for qemu-devel@nongnu.org; Thu, 16 Mar 2017 05:01:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53662) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1coRI6-00007S-2F for qemu-devel@nongnu.org; Thu, 16 Mar 2017 05:01:50 -0400 From: Juan Quintela Date: Thu, 16 Mar 2017 10:01:38 +0100 Message-Id: <20170316090141.13421-4-quintela@redhat.com> In-Reply-To: <20170316090141.13421-1-quintela@redhat.com> References: <20170316090141.13421-1-quintela@redhat.com> Subject: [Qemu-devel] [PULL 3/6] migration/block: Avoid invoking blk_drain too frequently List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: dgilbert@redhat.com, Lidong Chen From: Lidong Chen 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 Reviewed-by: Fam Zheng Signed-off-by: Juan Quintela --- 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; -- 2.9.3