Commit 4c0cbd6f authored by Fam Zheng's avatar Fam Zheng Committed by Jeff Cody
Browse files

block/mirror: Sleep periodically during bitmap scanning 



Before, we only yield after initializing dirty bitmap, where the QMP
command would return. That may take very long, and guest IO will be
blocked.

Add sleep points like the later mirror iterations.

Signed-off-by: default avatarFam Zheng <famz@redhat.com>
Reviewed-by: default avatarWen Congyang <wency@cn.fujitsu.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Message-id: 1431486673-19280-1-git-send-email-famz@redhat.com
Signed-off-by: default avatarJeff Cody <jcody@redhat.com>
parent 661725da

block/mirror.c

+12 −1
Original line number Diff line number Diff line
@@ -444,11 +444,23 @@ static void coroutine_fn mirror_run(void *opaque) 
    sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS;

    mirror_free_init(s);



    last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);

    if (!s->is_none_mode) {

        /* First part, loop on the sectors and initialize the dirty bitmap.  */

        BlockDriverState *base = s->base;

        for (sector_num = 0; sector_num < end; ) {

            int64_t next = (sector_num | (sectors_per_chunk - 1)) + 1;

            int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);



            if (now - last_pause_ns > SLICE_TIME) {

                last_pause_ns = now;

                block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, 0);

            }



            if (block_job_is_cancelled(&s->common)) {

                goto immediate_exit;

            }



            ret = bdrv_is_allocated_above(bs, base,

                                          sector_num, next - sector_num, &n);
@@ -467,7 +479,6 @@ static void coroutine_fn mirror_run(void *opaque) 
    }



    bdrv_dirty_iter_init(s->dirty_bitmap, &s->hbi);

    last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);

    for (;;) {

        uint64_t delay_ns = 0;

        int64_t cnt;