linux/block
Tejun Heo 54c52e10dc blk-iocost: switch to fixed non-auto-decaying use_delay
The use_delay mechanism was introduced by blk-iolatency to hold memory
allocators accountable for the reclaim and other shared IOs they cause. The
duration of the delay is dynamically balanced between iolatency increasing the
value on each target miss and it auto-decaying as time passes and threads get
delayed on it.

While this works well for iolatency, iocost's control model isn't compatible
with it. There is no repeated "violation" events which can be balanced against
auto-decaying. iocost instead knows how much a given cgroup is over budget and
wants to prevent that cgroup from issuing IOs while over budget. Until now,
iocost has been adding the cost of force-issued IOs. However, this doesn't
reflect the amount which is already over budget and is simply not enough to
counter the auto-decaying allowing anon-memory leaking low priority cgroup to
go over its alloted share of IOs.

As auto-decaying doesn't make much sense for iocost, this patch introduces a
different mode of operation for use_delay - when blkcg_set_delay() are used
insted of blkcg_add/use_delay(), the delay duration is not auto-decayed until it
is explicitly cleared with blkcg_clear_delay(). iocost is updated to keep the
delay duration synchronized to the budget overage amount.

With this change, iocost can effectively police cgroups which generate
significant amount of force-issued IOs.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-30 15:54:45 -06:00
..
partitions block: simplify block device syncing in bdev_del_partition 2020-04-20 11:32:59 -06:00
badblocks.c block: switch all files cleared marked as GPLv2 to SPDX tags 2019-04-30 16:11:57 -06:00
bfq-cgroup.c block, bfq: invoke flush_idle_tree after reparent_active_queues in pd_offline 2020-03-21 14:31:03 -06:00
bfq-iosched.c block, bfq: turn put_queue into release_process_ref in __bfq_bic_change_cgroup 2020-03-21 14:31:00 -06:00
bfq-iosched.h block, bfq: turn put_queue into release_process_ref in __bfq_bic_change_cgroup 2020-03-21 14:31:00 -06:00
bfq-wf2q.c block, bfq: get a ref to a group when adding it to a service tree 2020-02-03 06:58:15 -07:00
bio-integrity.c block: fix memleak of bio integrity data 2019-12-05 11:38:36 -07:00
bio.c block: move bio_map_* to blk-map.c 2020-03-27 12:04:34 -06:00
blk-cgroup-rwstat.c blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT 2019-11-07 12:28:13 -07:00
blk-cgroup-rwstat.h blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT 2019-11-07 12:28:13 -07:00
blk-cgroup.c blk-iocost: switch to fixed non-auto-decaying use_delay 2020-04-30 15:54:45 -06:00
blk-core.c block: add a bio_queue_enter helper 2020-04-29 09:33:26 -06:00
blk-exec.c block: account statistics for passthrough requests 2019-10-10 17:52:31 -06:00
blk-flush.c Revert "blkdev: check for valid request queue before issuing flush" 2020-03-27 10:23:44 -06:00
blk-integrity.c block: centralize PI remapping logic to the block layer 2019-09-17 20:03:49 -06:00
blk-ioc.c block: Fix use-after-free issue accessing struct io_cq 2020-03-12 07:07:38 -06:00
blk-iocost.c blk-iocost: switch to fixed non-auto-decaying use_delay 2020-04-30 15:54:45 -06:00
blk-iolatency.c blkcg: s/RQ_QOS_CGROUP/RQ_QOS_LATENCY/ 2019-08-28 21:17:08 -06:00
blk-lib.c block: fix 32 bit overflow in __blkdev_issue_discard() 2018-11-14 08:17:18 -07:00
blk-map.c block: remove RQF_COPY_USER 2020-04-22 10:47:06 -06:00
blk-merge.c block: replace BIO_QUEUE_ENTERED with BIO_CGROUP_ACCT 2020-04-29 09:33:26 -06:00
blk-mq-cpumap.c blk-mq: balance mapping between present CPUs and queues 2019-08-04 21:43:12 -06:00
blk-mq-debugfs-zoned.c block: Cleanup license notice 2019-01-17 21:21:40 -07:00
blk-mq-debugfs.c block: remove RQF_COPY_USER 2020-04-22 10:47:06 -06:00
blk-mq-debugfs.h blk-mq: no need to check return value of debugfs_create functions 2019-06-13 03:00:30 -06:00
blk-mq-pci.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq-rdma.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq-sched.c blk-mq: make function '__blk_mq_sched_dispatch_requests' static 2020-04-29 09:16:53 -06:00
blk-mq-sched.h block: blk-mq: Remove blk_mq_sched_started_request and started_request 2019-07-23 07:25:09 -06:00
blk-mq-sysfs.c blk-mq: make sure that line break can be printed 2019-11-04 07:14:10 -07:00
blk-mq-tag.c blk-mq: Remove some unused function arguments 2020-02-26 10:34:41 -07:00
blk-mq-tag.h blk-mq: Remove some unused function arguments 2020-02-26 10:34:41 -07:00
blk-mq-virtio.c blk-mq: Fix typo in comment 2020-03-17 20:55:21 +01:00
blk-mq.c block: bypass ->make_request_fn for blk-mq drivers 2020-04-25 09:45:44 -06:00
blk-mq.h blk-mq: Remove some unused function arguments 2020-02-26 10:34:41 -07:00
blk-pm.c block: bypass blk_set_runtime_active for uninitialized q->dev 2019-09-12 07:11:56 -06:00
blk-pm.h block: remove the queue_lock indirection 2018-11-15 12:17:28 -07:00
blk-rq-qos.c blk-wbt: fix performance regression in wbt scale_up/scale_down 2019-10-06 09:26:41 -06:00
blk-rq-qos.h blk-rq-qos: fix first node deletion of rq_qos_del() 2019-10-15 10:13:13 -06:00
blk-settings.c block: move dma drain handling to scsi 2020-04-22 10:47:35 -06:00
blk-softirq.c block: Don't disable interrupts in trigger_softirq() 2019-11-18 07:29:22 -07:00
blk-stat.c blk-stat: Optimise blk_stat_add() 2019-10-07 21:19:10 -06:00
blk-stat.h block: deactivate blk_stat timer in wbt_disable_default() 2018-12-12 06:47:51 -07:00
blk-sysfs.c block: Remove "dying" checks from sysfs callbacks 2019-10-07 08:31:59 -06:00
blk-throttle.c blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT 2019-11-07 12:28:13 -07:00
blk-timeout.c block: add SPDX tags to block layer files missing licensing information 2019-04-30 16:12:03 -06:00
blk-wbt.c blk-wbt: Use tracepoint_string() for wbt_step tracepoint string literals 2020-04-17 08:21:44 -06:00
blk-wbt.h block/rq_qos: implement rq_qos_ops->queue_depth_changed() 2019-08-28 21:17:07 -06:00
blk-zoned.c for-5.7/drivers-2020-03-29 2020-03-30 11:43:51 -07:00
blk.h block: remove create_io_context 2020-04-25 09:44:40 -06:00
bounce.c block: remove the i argument to bio_for_each_segment_all 2019-04-30 09:26:13 -06:00
bsg-lib.c block: Fix the type of 'sts' in bsg_queue_rq() 2019-12-20 11:52:01 -07:00
bsg.c compat_ioctl: bsg: add handler 2020-01-03 09:33:21 +01:00
cmdline-parser.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
elevator.c Merge branch 'for-linus' into for-5.5/block 2019-11-07 12:27:19 -07:00
genhd.c block: fold bdev_unhash_inode into invalidate_partition 2020-04-20 11:33:00 -06:00
ioctl.c block: refactor blkpg_ioctl 2020-04-20 11:32:59 -06:00
ioprio.c docs: block: convert to ReST 2019-07-15 09:20:27 -03:00
Kconfig block: Allow t10-pi to be modular 2020-01-06 20:59:04 -07:00
Kconfig.iosched blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT 2019-11-07 12:28:13 -07:00
kyber-iosched.c blk-mq: remove blk_mq_put_ctx() 2019-07-02 21:03:27 -06:00
Makefile block: merge partition-generic.c and check.c 2020-03-24 07:57:08 -06:00
mq-deadline.c block: Introduce elevator features 2019-09-05 19:52:33 -06:00
opal_proto.h block: sed-opal: Change the check condition for regular session validity 2020-03-12 08:00:10 -06:00
scsi_ioctl.c scsi: core: Allow non-root users to perform ZBC commands 2020-03-16 18:26:31 -04:00
sed-opal.c block: sed-opal: Change the check condition for regular session validity 2020-03-12 08:00:10 -06:00
t10-pi.c block: Allow t10-pi to be modular 2020-01-06 20:59:04 -07:00