On 3/19/21 12:48 AM, Ming Lei wrote: > Hi, > > Add per-task io poll context for holding HIPRI blk-mq/underlying bios > queued from bio based driver's io submission context, and reuse one bio > padding field for storing 'cookie' returned from submit_bio() for these > bios. Also explicitly end these bios in poll context by adding two > new bio flags. > > In this way, we needn't to poll all underlying hw queues any more, > which is implemented in Jeffle's patches. And we can just poll hw queues > in which there is HIPRI IO queued. > > Usually io submission and io poll share same context, so the added io > poll context data is just like one stack variable, and the cost for > saving bios is cheap. > > Any comments are welcome. > > V2: > - address queue depth scalability issue reported by Jeffle via bio > group list. Reuse .bi_end_io for linking bios which share same > .bi_end_io, and support 32 such groups in submit queue. With this way, > the scalability issue caused by kfifio is solved. Before really > ending bio, .bi_end_io is recovered from the group head. I have retested this latest version, and it seems the scaling issue has been fixed at the first glance. Test results with the latest version: 3-threads dm-stripe-3 targets (12k randread IOPS, unit K) 317 -> 409 (iodepth=128) Compared to the test results of v1: 3-threads dm-stripe-3 targets (12k randread IOPS, unit K) 313 -> 349 (iodepth=128, kfifo queue depth =128) 313 -> 409 (iodepth=32, kfifo queue depth =128) 314 -> 409 (iodepth=128, kfifo queue depth =512) > > > Jeffle Xu (4): > block/mq: extract one helper function polling hw queue > block: add queue_to_disk() to get gendisk from request_queue > block: add poll_capable method to support bio-based IO polling > dm: support IO polling for bio-based dm device > > Ming Lei (9): > block: add helper of blk_queue_poll > block: add one helper to free io_context > block: add helper of blk_create_io_context > block: create io poll context for submission and poll task > block: add req flag of REQ_TAG > block: add new field into 'struct bvec_iter' > block: prepare for supporting bio_list via other link > block: use per-task poll context to implement bio based io poll > blk-mq: limit hw queues to be polled in each blk_poll() > > block/bio.c | 5 + > block/blk-core.c | 248 ++++++++++++++++++++++++++++++++-- > block/blk-ioc.c | 12 +- > block/blk-mq.c | 232 ++++++++++++++++++++++++++++++- > block/blk-sysfs.c | 14 +- > block/blk.h | 55 ++++++++ > drivers/md/dm-table.c | 24 ++++ > drivers/md/dm.c | 14 ++ > drivers/nvme/host/core.c | 2 +- > include/linux/bio.h | 132 +++++++++--------- > include/linux/blk_types.h | 20 ++- > include/linux/blkdev.h | 4 + > include/linux/bvec.h | 9 ++ > include/linux/device-mapper.h | 1 + > include/linux/iocontext.h | 2 + > include/trace/events/kyber.h | 6 +- > 16 files changed, 686 insertions(+), 94 deletions(-) > -- Thanks, Jeffle
