[dm-devel] [PATCH V3 00/13] block: support bio based io polling
Ming Lei
ming.lei at redhat.com
Wed Mar 24 12:19:14 UTC 2021
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.
V3:
- fix cookie returned for bio based driver, as suggested by Jeffle
Xu
- draining pending bios when submission context is exiting
- patch style and comment fix, as suggested by Mike
- allow poll context data to be NULL by always polling on submission
queue
- remove RFC, and reviewed-by
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.
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_POLL_CTX
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 polling
blk-mq: limit hw queues to be polled in each blk_poll()
block/bio.c | 5 +
block/blk-core.c | 251 ++++++++++++++++++++++++++--
block/blk-ioc.c | 14 +-
block/blk-mq.c | 300 +++++++++++++++++++++++++++++++++-
block/blk-sysfs.c | 14 +-
block/blk.h | 65 ++++++++
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 | 22 ++-
include/linux/blkdev.h | 4 +
include/linux/bvec.h | 8 +
include/linux/device-mapper.h | 1 +
include/linux/iocontext.h | 2 +
include/trace/events/kyber.h | 6 +-
16 files changed, 770 insertions(+), 94 deletions(-)
--
2.29.2
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