Messages in this thread | | | From | Jens Axboe <> | Subject | [PATCHSET/RFC v2] Make legacy IO schedulers work with blk-mq | Date | Mon, 5 Dec 2016 11:26:59 -0700 |
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Version 2 of the hack/patchset, that enables blk-mq to use the legacy IO schedulers with single queue devices. Original posting is here:
https://marc.info/?l=linux-block&m=148073493203664&w=2
You can also found this version in the following git branch:
git://git.kernel.dk/linux-block blk-mq-legacy-sched.2
and new developments/fixes will happen in the 'blk-mq-legacy-sched' branch.
Changes since v1:
- Remove the default 'deadline' hard wiring, and provide Kconfig entries to set the blk-mq scheduler. This now works like for legacy devices.
- Rename blk_use_mq_path() to blk_use_sched_path() to make it more clear. Suggested by Johannes Thumshirn.
- Fixup a spot where we did not use the accessor function to determine what path to use.
- Flush mq software queues, even if IO scheduler managed. This should make paths work that are MQ aware, and using only MQ interfaces.
- Cleanup free path of MQ request.
- Account when IO was queued to a hardware context, similarly to the regular MQ path.
- Add BLK_MQ_F_NO_SCHED flag, so that drivers can explicitly ask for no scheduling on a queue. Add this for NVMe admin queues.
- Kill BLK_MQ_F_SCHED, since we now have Kconfig entries for setting the desired IO scheduler.
- Fix issues with live scheduler switching through sysfs. Should now be solid, even with lots of IO running on the device.
- Drop null_blk and SCSI changes, not needed anymore.
block/Kconfig.iosched | 29 ++++ block/blk-core.c | 77 ++++++----- block/blk-exec.c | 12 + block/blk-flush.c | 40 +++-- block/blk-merge.c | 5 block/blk-mq.c | 332 +++++++++++++++++++++++++++++++++++++++++++++--- block/blk-mq.h | 1 block/blk-sysfs.c | 2 block/blk.h | 16 ++ block/cfq-iosched.c | 22 ++- block/elevator.c | 125 ++++++++++++------ drivers/nvme/host/pci.c | 1 include/linux/blk-mq.h | 1 include/linux/blkdev.h | 2 14 files changed, 555 insertions(+), 110 deletions(-)
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