From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53524) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNglq-00058m-Ed for qemu-devel@nongnu.org; Thu, 14 Jul 2016 09:33:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bNgln-0007tz-Bm for qemu-devel@nongnu.org; Thu, 14 Jul 2016 09:33:42 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:30397 helo=relay.sw.ru) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNglm-0007sv-St for qemu-devel@nongnu.org; Thu, 14 Jul 2016 09:33:39 -0400 From: "Denis V. Lunev" Date: Thu, 14 Jul 2016 16:33:29 +0300 Message-Id: <1468503209-19498-9-git-send-email-den@openvz.org> In-Reply-To: <1468503209-19498-1-git-send-email-den@openvz.org> References: <1468503209-19498-1-git-send-email-den@openvz.org> Subject: [Qemu-devel] [PATCH v3 8/8] mirror: improve performance of mirroring of empty disk List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org, qemu-devel@nongnu.org Cc: den@openvz.org, Stefan Hajnoczi , Kevin Wolf , Max Reitz , Jeff Cody , Eric Blake We should not take into account zero blocks for delay calculations. They are not read and thus IO throttling is not required. In the other case VM migration with 16 Tb QCOW2 disk with 4 Gb of data takes days. Signed-off-by: Denis V. Lunev Reviewed-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Fam Zheng CC: Stefan Hajnoczi CC: Kevin Wolf CC: Max Reitz CC: Jeff Cody CC: Eric Blake --- block/mirror.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/block/mirror.c b/block/mirror.c index ae70c3b..1787a6a 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -323,6 +323,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) int nb_chunks = 1; int64_t end = s->bdev_length / BDRV_SECTOR_SIZE; int sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; + bool write_zeroes_ok = bdrv_can_write_zeroes_with_unmap(blk_bs(s->target)); sector_num = hbitmap_iter_next(&s->hbi); if (sector_num < 0) { @@ -373,7 +374,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) bitmap_set(s->in_flight_bitmap, sector_num / sectors_per_chunk, nb_chunks); while (nb_chunks > 0 && sector_num < end) { int ret; - int io_sectors; + int io_sectors, io_sectors_acct; BlockDriverState *file; enum MirrorMethod { MIRROR_METHOD_COPY, @@ -410,12 +411,17 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) switch (mirror_method) { case MIRROR_METHOD_COPY: io_sectors = mirror_do_read(s, sector_num, io_sectors); + io_sectors_acct = io_sectors; break; case MIRROR_METHOD_ZERO: - mirror_do_zero_or_discard(s, sector_num, io_sectors, false); - break; case MIRROR_METHOD_DISCARD: - mirror_do_zero_or_discard(s, sector_num, io_sectors, true); + mirror_do_zero_or_discard(s, sector_num, io_sectors, + mirror_method == MIRROR_METHOD_DISCARD); + if (write_zeroes_ok) { + io_sectors_acct = 0; + } else { + io_sectors_acct = io_sectors; + } break; default: abort(); @@ -423,7 +429,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) assert(io_sectors); sector_num += io_sectors; nb_chunks -= DIV_ROUND_UP(io_sectors, sectors_per_chunk); - delay_ns += ratelimit_calculate_delay(&s->limit, io_sectors); + delay_ns += ratelimit_calculate_delay(&s->limit, io_sectors_acct); } return delay_ns; } -- 2.5.0