Hi, The 1st patch converts two start/stop queue into quiesce/unquiesce in xen-blkfront. The 2nd patch uses blk_mq_run_hw_queues() in SCSI becasue the queue won't be stopped at all. The 3rd patch prepares for introducing congestion control for blk-mq. The 4th patch uses EWMA to estimate congestion threshold. The 5th patch uses the estimated congestion threshold to dectect congestion. Once the congestion is found, queue is stopped, and will be restarted if the condition is invalid. The 6th patch unexports several APIs for starting/stopping queue, then the STOPPED state of queue becomes a internal state, and it is invisible to drivers now. This patchset is against on Sagi Grimberg's patchset of "[PATCH v3 0/8] correct quiescing in several block drivers", which can be found in: http://marc.info/?t=149927415900006&r=1&w=2 Any comments are welcome! Ming Lei (6): xen-blkfront: avoid to use start/stop queue SCSI: use blk_mq_run_hw_queues() in scsi_kick_queue() blk-mq: send the request to dispatch list if direct issue returns busy blk-mq: use EWMA to estimate congestion threshold blk-mq: introduce basic congestion control blk-mq: unexport APIs for start/stop queues block/blk-mq.c | 143 ++++++++++++++++++------------------------- block/blk-mq.h | 11 ++++ drivers/block/virtio_blk.c | 7 --- drivers/block/xen-blkfront.c | 28 ++------- drivers/md/dm-rq.c | 1 - drivers/nvme/host/fc.c | 4 -- drivers/scsi/scsi_lib.c | 5 +- include/linux/blk-mq.h | 10 +-- 8 files changed, 79 insertions(+), 130 deletions(-) -- 2.9.4
