From b7d5062c9cf53f21a555843775392dc03364bbff Mon Sep 17 00:00:00 2001 From: "Denis V. Lunev" Date: Thu, 14 Jul 2016 16:33:27 +0300 Subject: [PATCH] mirror: optimize dirty bitmap filling in mirror_run a bit There is no need to scan allocation tables if we have mark_all_dirty flag set. Just mark it all dirty. Signed-off-by: Denis V. Lunev Reviewed-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Eric Blake Reviewed-by: John Snow Reviewed-by: Fam Zheng Message-id: 1468503209-19498-7-git-send-email-den@openvz.org CC: Stefan Hajnoczi CC: Kevin Wolf CC: Max Reitz CC: Jeff Cody Signed-off-by: Jeff Cody --- block/mirror.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/block/mirror.c b/block/mirror.c index 0e74666d01..b7b1ded30f 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -533,11 +533,15 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) BlockDriverState *base = s->base; BlockDriverState *bs = blk_bs(s->common.blk); BlockDriverState *target_bs = blk_bs(s->target); - bool mark_all_dirty = base == NULL && !bdrv_has_zero_init(target_bs); int ret, n; end = s->bdev_length / BDRV_SECTOR_SIZE; + if (base == NULL && !bdrv_has_zero_init(target_bs)) { + bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, end); + return 0; + } + /* First part, loop on the sectors and initialize the dirty bitmap. */ for (sector_num = 0; sector_num < end; ) { /* Just to make sure we are not exceeding int limit. */ @@ -556,7 +560,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) } assert(n > 0); - if (ret == 1 || mark_all_dirty) { + if (ret == 1) { bdrv_set_dirty_bitmap(s->dirty_bitmap, sector_num, n); } sector_num += n;