[PATCH V2 0/3] blk-mq: improve IO perf in case of none io sched

Ming Lei
2018-06-29T08:12:49Z

Hi,

The 1st 2 patch improves ctx->lock uses, and it is observed that IOPS
may be improved by ~5% in rand IO test on MegaRaid SAS run by Kashyap.

The 3rd patch fixes rand IO performance regression on MegaRaid SAS
test, still reported by Kashyap.

V2:
- fix list corruption in patch 1/3

Ming Lei (3):
blk-mq: use list_splice_tail_init() to insert requests
blk-mq: only attempt to merge bio if there is rq in sw queue
blk-mq: dequeue request one by one from sw queue iff hctx is busy

block/blk-mq-sched.c | 14 ++++----------
block/blk-mq.c | 38 ++++++++++++++++++++++++++++++--------
include/linux/blk-mq.h | 1 +
3 files changed, 35 insertions(+), 18 deletions(-)

Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>

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2.9.5