[v6,00/11] mq-deadline: Improve support for zoned block devices

Message

Bart Van Assche May 17, 2023, 5:42 p.m. UTC

Hi Jens,

This patch series improves support for zoned block devices in the mq-deadline
scheduler by preserving the order of requeued writes (REQ_OP_WRITE and
REQ_OP_WRITE_ZEROES).

Please consider this patch series for the next merge window.

Thanks,

Bart.

Changes compared to v5:
- Added a patch with a grammar fix for a source code comment.
- Renamed op_is_zoned_write() into op_needs_zoned_write_locking().
- Dropped patch "block: mq-deadline: Improve deadline_skip_seq_writes()".

Changes compared to v4:
- Changed blk_rq_is_seq_zoned_write() into an inline function.
- Reworked patch "Reduce lock contention" such that all merged requests are
  freed at once.

Changes compared to v3:
- Addressed Christoph's review feedback.
- Dropped patch "block: Micro-optimize blk_req_needs_zone_write_lock()".
- Added three new patches:
  * block: Fix the type of the second bdev_op_is_zoned_write() argument
  * block: Introduce op_is_zoned_write()
  * block: mq-deadline: Reduce lock contention

Changes compared to v2:
- In the patch that micro-optimizes blk_req_needs_zone_write_lock(), inline
  bdev_op_is_zoned_write() instead of modifying it.
- In patch "block: Introduce blk_rq_is_seq_zoned_write()", converted "case
  REQ_OP_ZONE_APPEND" into a source code comment.
- Reworked deadline_skip_seq_writes() as suggested by Christoph.
- Dropped the patch that disabled head insertion for zoned writes.
- Dropped patch "mq-deadline: Fix a race condition related to zoned writes".
- Reworked handling of requeued requests: the 'next_rq' pointer has been
  removed and instead the position of the most recently dispatched request is
  tracked.
- Dropped the patches for tracking zone capacity and for restricting the number
  of active zones.

Changes compared to v1:
- Left out the patches related to request insertion and requeuing since
  Christoph is busy with reworking these patches.
- Added a patch for enforcing the active zone limit.

Bart Van Assche (11):
  block: mq-deadline: Add a word in a source code comment
  block: Simplify blk_req_needs_zone_write_lock()
  block: Fix the type of the second bdev_op_is_zoned_write() argument
  block: Introduce op_needs_zoned_write_locking()
  block: Introduce blk_rq_is_seq_zoned_write()
  block: mq-deadline: Clean up deadline_check_fifo()
  block: mq-deadline: Simplify deadline_skip_seq_writes()
  block: mq-deadline: Reduce lock contention
  block: mq-deadline: Track the dispatch position
  block: mq-deadline: Handle requeued requests correctly
  block: mq-deadline: Fix handling of at-head zoned writes

 block/blk-zoned.c      |   8 +--
 block/mq-deadline.c    | 125 +++++++++++++++++++++++++++--------------
 include/linux/blk-mq.h |  17 ++++++
 include/linux/blkdev.h |  13 +++--
 4 files changed, 110 insertions(+), 53 deletions(-)

Comments

Jens Axboe May 19, 2023, 1:50 a.m. UTC | #1

On Wed, 17 May 2023 10:42:18 -0700, Bart Van Assche wrote:
> This patch series improves support for zoned block devices in the mq-deadline
> scheduler by preserving the order of requeued writes (REQ_OP_WRITE and
> REQ_OP_WRITE_ZEROES).
> 
> Please consider this patch series for the next merge window.
> 
> Thanks,
> 
> [...]

Applied, thanks!

[01/11] block: mq-deadline: Add a word in a source code comment
        commit: 45b46b6f157169b452772430566772506e25687a
[02/11] block: Simplify blk_req_needs_zone_write_lock()
        commit: 4f51644ccff1e4bf159e86da3d9695a1a33ca231
[03/11] block: Fix the type of the second bdev_op_is_zoned_write() argument
        commit: 3ddbe2a7e0d4a155a805f69c906c9beed30d4cc4
[04/11] block: Introduce op_needs_zoned_write_locking()
        commit: a370798201b537f78288e4ef5e0f7fc70889e7ee
[05/11] block: Introduce blk_rq_is_seq_zoned_write()
        commit: 19821fee3ed42e5b294e95814892d0ad6a9890c9
[06/11] block: mq-deadline: Clean up deadline_check_fifo()
        commit: e0d85cde95bba7d40caa3bf9bc41ee810f0e96df
[07/11] block: mq-deadline: Simplify deadline_skip_seq_writes()
        commit: 3b463cbea908a9c8d4b9eda09765070506864cbe
[08/11] block: mq-deadline: Reduce lock contention
        commit: b2097bd24b438d49d82a5c317be4dc74b626236a
[09/11] block: mq-deadline: Track the dispatch position
        commit: 83c46ed675579fe84354bd07b0d81b525a2b1ebb
[10/11] block: mq-deadline: Handle requeued requests correctly
        commit: 0effb390c4bac1a484f0ca6ad3f1d183fcde882b
[11/11] block: mq-deadline: Fix handling of at-head zoned writes
        commit: a036e698c231ba884daa37196be3ac6c6dce1d75

Best regards,