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[Qemu-devel] [PULL 07/14] mirror: efficiently zero out target
From: |
Jeff Cody |
Subject: |
[Qemu-devel] [PULL 07/14] mirror: efficiently zero out target |
Date: |
Tue, 19 Jul 2016 20:20:55 -0400 |
From: "Denis V. Lunev" <address@hidden>
With a bdrv_co_write_zeroes method on a target BDS and when this method
is working as indicated by the bdrv_can_write_zeroes_with_unmap(), zeroes
will not be placed into the wire. Thus the target could be very efficiently
zeroed out. This should be done with the largest chunk possible.
Signed-off-by: Denis V. Lunev <address@hidden>
Reviewed-by: Vladimir Sementsov-Ogievskiy<address@hidden>
Reviewed-by: Fam Zheng <address@hidden>
Message-id: address@hidden
CC: Stefan Hajnoczi <address@hidden>
CC: Kevin Wolf <address@hidden>
CC: Max Reitz <address@hidden>
CC: Jeff Cody <address@hidden>
CC: Eric Blake <address@hidden>
Signed-off-by: Jeff Cody <address@hidden>
---
block/mirror.c | 28 ++++++++++++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index b7b1ded..0262b03 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -538,8 +538,32 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob
*s)
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;
+ if (!bdrv_can_write_zeroes_with_unmap(target_bs)) {
+ bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, end);
+ return 0;
+ }
+
+ for (sector_num = 0; sector_num < end; ) {
+ int nb_sectors = MIN(end - sector_num,
+ QEMU_ALIGN_DOWN(INT_MAX, s->granularity) >> BDRV_SECTOR_BITS);
+
+ mirror_throttle(s);
+
+ if (block_job_is_cancelled(&s->common)) {
+ return 0;
+ }
+
+ if (s->in_flight >= MAX_IN_FLIGHT) {
+ trace_mirror_yield(s, s->in_flight, s->buf_free_count, -1);
+ mirror_wait_for_io(s);
+ continue;
+ }
+
+ mirror_do_zero_or_discard(s, sector_num, nb_sectors, false);
+ sector_num += nb_sectors;
+ }
+
+ mirror_drain(s);
}
/* First part, loop on the sectors and initialize the dirty bitmap. */
--
1.9.3
- [Qemu-devel] [PULL 00/14] Block patches, Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 02/14] mirror: make sectors_in_flight int64_t, Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 03/14] mirror: create mirror_throttle helper, Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 04/14] mirror: create mirror_dirty_init helper for mirror_run, Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 01/14] dirty-bitmap: operate with int64_t amount, Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 05/14] block: remove extra condition in bdrv_can_write_zeroes_with_unmap, Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 06/14] mirror: optimize dirty bitmap filling in mirror_run a bit, Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 08/14] mirror: improve performance of mirroring of empty disk, Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 07/14] mirror: efficiently zero out target,
Jeff Cody <=
- [Qemu-devel] [PULL 09/14] mirror: fix request throttling in drive-mirror, Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 10/14] block/gluster: rename [server, volname, image] -> [host, volume, path], Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 11/14] block/gluster: code cleanup, Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 12/14] block/gluster: deprecate rdma support, Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 14/14] block/gluster: add support for multiple gluster servers, Jeff Cody, 2016/07/19
- [Qemu-devel] [PULL 13/14] block/gluster: using new qapi schema, Jeff Cody, 2016/07/19
- Re: [Qemu-devel] [PULL 00/14] Block patches, Peter Maydell, 2016/07/20