Hi Jens, 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. V6: - move poll code into block/blk-poll.c, as suggested by Christoph - define bvec_iter as __packed, and add one new field to bio, as suggested by Christoph - re-organize patch order, as suggested by Christoph - add one flag for checking if the disk is capable of bio polling and remove .poll_capable(), as suggested by Christoph - fix type of .bi_poll V5: - fix one use-after-free issue in case that polling is from another context: adds one new cookie of BLK_QC_T_NOT_READY for preventing this issue in patch 8/12 - add reviewed-by & tested-by tag V4: - cover one more test_bit(QUEUE_FLAG_POLL, ...) suggested by Jeffle(01/12) - drop patch of 'block: add helper of blk_create_io_context' - add new helper of blk_create_io_poll_context() (03/12) - drain submission queues in exit_io_context(), suggested by Jeffle(08/13) - considering shared io context case for blk_bio_poll_io_drain() (08/13) - fix one issue in blk_bio_poll_pack_groups() as suggested by Jeffle(08/13) - add reviewed-by tag 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 (2): block: extract one helper function polling hw queue dm: support IO polling for bio-based dm device Ming Lei (10): block: add helper of blk_queue_poll block: define 'struct bvec_iter' as packed block: add one helper to free io_context block: move block polling code into one dedicated source file block: prepare for supporting bio_list via other link block: create io poll context for submission and poll task block: add req flag of REQ_POLL_CTX block: use per-task poll context to implement bio based io polling block: limit hw queues to be polled in each blk_poll() block: allow to control FLAG_POLL via sysfs for bio poll capable queue block/Makefile | 3 +- block/bio.c | 5 + block/blk-core.c | 68 +++- block/blk-ioc.c | 15 +- block/blk-mq.c | 231 ------------- block/blk-mq.h | 40 +++ block/blk-poll.c | 632 ++++++++++++++++++++++++++++++++++ block/blk-sysfs.c | 16 +- block/blk.h | 112 ++++++ drivers/md/dm-table.c | 24 ++ drivers/md/dm.c | 2 + drivers/nvme/host/core.c | 2 +- include/linux/bio.h | 132 +++---- include/linux/blk_types.h | 31 +- include/linux/blkdev.h | 1 + include/linux/bvec.h | 2 +- include/linux/device-mapper.h | 1 + include/linux/genhd.h | 2 + include/linux/iocontext.h | 2 + 19 files changed, 1003 insertions(+), 318 deletions(-) create mode 100644 block/blk-poll.c -- 2.29.2 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel
