Changes in v2: - Patch "block-backend: Introduce blk_drain() and replace blk_drain_all()" splitted to two. - blk_drain() moved to above virtio_blk_data_plane_stop().
During reset the aio_poll() function is called at least amount_of_disks^2 times: for_each disk virtio_blk_reset() bdrv_drain_all() for_each disk aio_poll() For example, startup with 1000 disks takes over 13 minutes. Patches 1 and 2 removes inner loop by using bdrv_drain() instead of bdrv_drain_all(). bdrv_drain() works on one disk at time. Since bdrv_drain_all() is still called in other places, patch 3 optimizes it for cases, where there are more disks than iothreads. Thanks. Alexander Yarygin (3): block-backend: Introduce blk_drain() virtio-blk: Use blk_drain() to drain IO requests block: Let bdrv_drain_all() to call aio_poll() for each AioContext block/block-backend.c | 5 +++++ block/io.c | 42 ++++++++++++++++++++++++++---------------- hw/block/virtio-blk.c | 11 ++++++----- include/sysemu/block-backend.h | 1 + 4 files changed, 38 insertions(+), 21 deletions(-) -- 1.9.1