Hello Jens,
The six patches in this patch series fix the queue lockup I reported
recently on the linux-block mailing list. Please consider these patches
for inclusion in the upstream kernel.
Thanks,
Bart.
Changes between v3 and v4:
- Addressed the review comments on version three of this series about the
patch that makes it safe to use RCU to iterate over .tag_list and also
about the runtime performance and use of short variable names in patch 2/5.
- Clarified the description of the patch that fixes the scsi-mq stall.
- Added a patch to fix a dm-mq queue stall.
Changes between v2 and v3:
- Removed the blk_mq_ops.restart_hctx function pointer again.
- Modified blk_mq_sched_restart_queues() such that only a single hardware
queue is restarted instead of multiple if hardware queues are shared.
- Introduced a new function in the block layer, namely
blk_mq_delay_run_hw_queue().
Changes between v1 and v2:
- Reworked scsi_restart_queues() such that it no longer takes the SCSI
host lock.
- Added two patches - one for exporting blk_mq_sched_restart_hctx() and
another one to make iterating with RCU over blk_mq_tag_set.tag_list safe.
Bart Van Assche (6):
blk-mq: Make it safe to use RCU to iterate over
blk_mq_tag_set.tag_list
blk-mq: Restart a single queue if tag sets are shared
blk-mq: Clarify comments in blk_mq_dispatch_rq_list()
blk-mq: Introduce blk_mq_delay_run_hw_queue()
scsi: Avoid that SCSI queues get stuck
dm rq: Avoid that request processing stalls sporadically
block/blk-mq-sched.c | 63 +++++++++++++++++++++++++++++++++++-------
block/blk-mq-sched.h | 16 +----------
block/blk-mq.c | 73 +++++++++++++++++++++++++++++++++++++++----------
drivers/md/dm-rq.c | 1 +
drivers/scsi/scsi_lib.c | 6 ++--
include/linux/blk-mq.h | 2 ++
include/linux/blkdev.h | 1 -
7 files changed, 118 insertions(+), 44 deletions(-)
--
2.12.0
