linux-stable/block
Jens Axboe 7b05bf7710 Revert "block/mq-deadline: Prioritize high-priority requests"
This reverts commit fb926032b3.

Zhen reports that this commit slows down mq-deadline on a 128 thread
box, going from 258K IOPS to 170-180K. My testing shows that Optane
gen2 IOPS goes from 2.3M IOPS to 1.2M IOPS on a 64 thread box.

Looking in detail at the code, the main culprit here is needing to sum
percpu counters in the dispatch hot path, leading to very high CPU
utilization there. To make matters worse, the code currently needs to
sum 2 percpu counters, and it does so in the most naive way of iterating
possible CPUs _twice_.

Since we're close to release, revert this commit and we can re-do it
with regular per-priority counters instead for the 5.15 kernel.

Link: https://lore.kernel.org/linux-block/20210826144039.2143-1-thunder.leizhen@huawei.com/
Reported-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-26 12:59:44 -06:00
..
partitions block/partitions/ldm.c: Fix a kernel-doc warning 2021-08-05 11:49:01 -06:00
badblocks.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
bfq-cgroup.c block, bfq: merge bursts of newly-created queues 2021-03-25 10:50:07 -06:00
bfq-iosched.c blk: Fix lock inversion between ioc lock and bfqd lock 2021-06-24 18:43:55 -06:00
bfq-iosched.h block, bfq: merge bursts of newly-created queues 2021-03-25 10:50:07 -06:00
bfq-wf2q.c block, bfq: always inject I/O of queues blocked by wakers 2021-03-25 10:50:07 -06:00
bio-integrity.c block: remove BLK_BOUNCE_ISA support 2021-04-06 09:28:17 -06:00
bio.c block: fix trace completion for chained bio 2021-06-24 09:53:50 -06:00
blk-cgroup-rwstat.c blk-cgroup: Fix the recursive blkg rwstat 2021-03-05 11:32:15 -07:00
blk-cgroup-rwstat.h
blk-cgroup.c blk-cgroup: prevent rcu_sched detected stalls warnings while iterating blkgs 2021-07-07 09:36:36 -06:00
blk-core.c blk-mq: fix kernel panic during iterating over flush request 2021-08-17 08:33:32 -06:00
blk-crypto-fallback.c block: rename BIO_MAX_PAGES to BIO_MAX_VECS 2021-03-11 07:47:48 -07:00
blk-crypto-internal.h block: make blk_crypto_rq_bio_prep() able to fail 2020-10-05 10:47:43 -06:00
blk-crypto.c dm: support key eviction from keyslot managers of underlying devices 2021-02-11 09:45:25 -05:00
blk-exec.c block: return errors from blk_execute_rq() 2021-06-30 15:35:45 -06:00
blk-flush.c blk-mq: fix is_flush_rq 2021-08-17 20:17:34 -06:00
blk-integrity.c block: remove the unused blk_integrity_merge_bio export 2020-10-06 07:29:53 -06:00
blk-ioc.c block: remove retry loop in ioc_release_fn() 2020-07-16 10:22:15 -06:00
blk-iocost.c blk-iocost: fix lockdep warning on blkcg->lock 2021-08-09 20:00:26 -06:00
blk-iolatency.c blk-iolatency: error out if blk_get_queue() failed in iolatency_set_limit() 2021-08-05 11:18:13 -06:00
blk-ioprio.c block: Introduce the ioprio rq-qos policy 2021-06-21 15:03:40 -06:00
blk-ioprio.h block: Introduce the ioprio rq-qos policy 2021-06-21 15:03:40 -06:00
blk-lib.c block: export blk_next_bio() 2021-06-17 15:51:20 +02:00
blk-map.c block: remove an incorrect check from blk_rq_append_bio 2021-04-12 06:45:12 -06:00
blk-merge.c block: fix discard request merge 2021-06-29 07:41:08 -06:00
blk-mq-cpumap.c blk-mq: remove the calling of local_memory_node() 2020-10-20 07:08:17 -06:00
blk-mq-debugfs-zoned.c
blk-mq-debugfs.c block: Introduce the ioprio rq-qos policy 2021-06-21 15:03:40 -06:00
blk-mq-debugfs.h
blk-mq-pci.c
blk-mq-rdma.c
blk-mq-sched.c blk-mq-sched: Fix blk_mq_sched_alloc_tags() error handling 2021-07-27 16:44:38 -06:00
blk-mq-sched.h blk: Fix lock inversion between ioc lock and bfqd lock 2021-06-24 18:43:55 -06:00
blk-mq-sysfs.c blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue 2020-10-09 12:46:28 -06:00
blk-mq-tag.c blk-mq: Use request queue-wide tags for tagset-wide sbitmap 2021-05-24 06:47:22 -06:00
blk-mq-tag.h blk-mq: Some tag allocation code refactoring 2021-05-24 06:47:22 -06:00
blk-mq-virtio.c
blk-mq.c blk-mq: fix is_flush_rq 2021-08-17 20:17:34 -06:00
blk-mq.h blk: Fix lock inversion between ioc lock and bfqd lock 2021-06-24 18:43:55 -06:00
blk-pm.c scsi: block: Fix a race in the runtime power management code 2020-12-09 11:41:41 -05:00
blk-pm.h block: Remove unused blk_pm_*() function definitions 2021-02-22 06:33:48 -07:00
blk-rq-qos.c rq-qos: fix missed wake-ups in rq_qos_throttle try two 2021-06-08 15:12:57 -06:00
blk-rq-qos.h block: Introduce the ioprio rq-qos policy 2021-06-21 15:03:40 -06:00
blk-settings.c block-5.13-2021-05-09 2021-05-09 13:25:14 -07:00
blk-stat.c blk-stat: make q->stats->lock irqsafe 2020-09-01 16:48:46 -06:00
blk-stat.h
blk-sysfs.c block: mark queue init done at the end of blk_register_queue 2021-06-16 08:41:50 -06:00
blk-throttle.c block: store a block_device pointer in struct bio 2021-01-24 18:17:20 -07:00
blk-timeout.c block: blk-timeout: delete duplicated word 2020-07-31 16:29:47 -06:00
blk-wbt.c blk-wbt: make sure throttle is enabled properly 2021-06-21 15:03:41 -06:00
blk-wbt.h blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled() 2021-06-21 15:03:41 -06:00
blk-zoned.c blk-zoned: Remove the definition of blk_zone_start() 2021-04-07 14:31:45 -06:00
blk.h blk-mq: fix is_flush_rq 2021-08-17 20:17:34 -06:00
bounce.c block: stop calling blk_queue_bounce for passthrough requests 2021-04-06 09:28:18 -06:00
bsg-lib.c block: remove REQ_OP_SCSI_{IN,OUT} 2021-06-30 15:34:19 -06:00
bsg.c block: remove REQ_OP_SCSI_{IN,OUT} 2021-06-30 15:34:19 -06:00
cmdline-parser.c
disk-events.c block: add the events* attributes to disk_attrs 2021-06-24 12:00:22 -06:00
elevator.c blk: Fix lock inversion between ioc lock and bfqd lock 2021-06-24 18:43:55 -06:00
genhd.c block: delay freeing the gendisk 2021-07-27 19:35:47 -06:00
ioctl.c block: move bd_part_count to struct gendisk 2021-06-01 07:45:27 -06:00
ioprio.c block: Fix sys_ioprio_set(.which=IOPRIO_WHO_PGRP) task iteration 2021-04-08 13:43:53 -06:00
Kconfig block: Introduce the ioprio rq-qos policy 2021-06-21 15:03:40 -06:00
Kconfig.iosched Revert "block/mq-deadline: Add cgroup support" 2021-08-11 13:47:26 -06:00
keyslot-manager.c - Fix DM integrity's HMAC support to provide enhanced security of 2021-02-22 10:22:54 -08:00
kyber-iosched.c kyber: make trace_block_rq call consistent with documentation 2021-08-06 16:40:47 -06:00
Makefile Revert "block/mq-deadline: Add cgroup support" 2021-08-11 13:47:26 -06:00
mq-deadline.c Revert "block/mq-deadline: Prioritize high-priority requests" 2021-08-26 12:59:44 -06:00
opal_proto.h
scsi_ioctl.c block: remove REQ_OP_SCSI_{IN,OUT} 2021-06-30 15:34:19 -06:00
sed-opal.c
t10-pi.c