Paolo Valente ac8b0cb415 block, bfq: do not plug I/O of in-service queue when harmful ... If the in-service bfq_queue is sync and remains temporarily idle, then I/O dispatching (from other queues) may be plugged. It may be dome for two reasons: either to boost throughput, or to preserve the bandwidth share of the in-service queue. In the first case, if the I/O of the in-service queue, when it finally arrives, consists only of one small I/O request, then it makes sense to plug even the I/O of the in-service queue. In fact, serving such a small request immediately is likely to lower throughput instead of boosting it, whereas waiting a little bit is likely to let that request grow, thanks to request merging, and become more profitable in terms of throughput (this is likely to happen exactly because the I/O of the queue has been detected to boost throughput). On the opposite end, if I/O dispatching is being plugged only to preserve the bandwidth of the in-service queue, then it would be better not to plug also the I/O of the in-service queue, because such a plugging is likely to cause only loss of bandwidth for the queue. Unfortunately, no distinction is made between the two cases, and the I/O of the in-service queue is always plugged in case just a small I/O request arrives. This commit draws this missing distinction and does not perform harmful plugging. Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>		2019-01-31 12:50:23 -07:00
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partitions	partitions/aix: append null character to print data from disk	2018-07-27 09:17:41 -06:00
Kconfig	Kconfig updates for v4.21	2018-12-29 13:03:29 -08:00
Kconfig.iosched	block: remove legacy IO schedulers	2018-11-07 13:42:32 -07:00
Makefile	block: remove legacy IO schedulers	2018-11-07 13:42:32 -07:00
badblocks.c	badblocks: fix wrong return value in badblocks_set if badblocks are disabled	2017-11-03 11:29:50 -07:00
bfq-cgroup.c	blkcg: fix ref count issue with bio_blkcg() using task_css	2018-12-07 22:26:36 -07:00
bfq-iosched.c	block, bfq: do not plug I/O of in-service queue when harmful	2019-01-31 12:50:23 -07:00
bfq-iosched.h	block, bfq: consider also ioprio classes in symmetry detection	2019-01-31 12:50:23 -07:00
bfq-wf2q.c	block, bfq: consider also ioprio classes in symmetry detection	2019-01-31 12:50:23 -07:00
bio-integrity.c	block: remove the bio_integrity_advance export	2018-12-16 08:33:57 -07:00
bio.c	for-4.21/block-20190102	2019-01-02 18:49:58 -08:00
blk-cgroup.c	blkcg: remove unused __blkg_release_rcu()	2018-12-21 08:47:58 -07:00
blk-core.c	Revert "block: cover another queue enter recursion via BIO_QUEUE_ENTERED"	2019-01-27 06:35:28 -07:00
blk-exec.c	block: remove dead elevator code	2018-11-07 13:42:32 -07:00
blk-flush.c	block: add queue_is_mq() helper	2018-11-16 08:34:06 -07:00
blk-integrity.c	block: merge BIOVEC_SEG_BOUNDARY into biovec_phys_mergeable	2018-09-24 12:33:57 -06:00
blk-ioc.c	block: remove the queue_lock indirection	2018-11-15 12:17:28 -07:00
blk-iolatency.c	block: fix blk-iolatency accounting underflow	2018-12-17 11:19:54 -07:00
blk-lib.c	block: fix 32 bit overflow in __blkdev_issue_discard()	2018-11-14 08:17:18 -07:00
blk-map.c	Merge branch 'for-4.16/block' of git://git.kernel.dk/linux-block	2018-01-29 11:51:49 -08:00
blk-merge.c	Revert "block: cover another queue enter recursion via BIO_QUEUE_ENTERED"	2019-01-27 06:35:28 -07:00
blk-mq-cpumap.c	blk-mq: initial support for multiple queue maps	2018-11-07 13:45:00 -07:00
blk-mq-debugfs-zoned.c	block: Cleanup license notice	2019-01-17 21:21:40 -07:00
blk-mq-debugfs.c	blk-mq: fix the cmd_flag_name array	2019-01-24 08:41:42 -07:00
blk-mq-debugfs.h	blk-mq-debugfs: support rq_qos	2018-12-16 19:53:47 -07:00
blk-mq-pci.c	blk-mq: initial support for multiple queue maps	2018-11-07 13:45:00 -07:00
blk-mq-rdma.c	blk-mq-rdma: pass in queue map to blk_mq_rdma_map_queues	2018-12-13 09:59:08 +01:00
blk-mq-sched.c	blk-mq: fix dispatch from sw queue	2018-12-17 11:19:54 -07:00
blk-mq-sched.h	block: mq-deadline: Fix write completion handling	2018-12-17 11:19:39 -07:00
blk-mq-sysfs.c	blk-mq: export hctx->type in debugfs instead of sysfs	2018-12-17 05:44:45 -07:00
blk-mq-tag.c	sbitmap: optimize wakeup check	2018-11-30 14:48:04 -07:00
blk-mq-tag.h	Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-block	2017-11-14 15:32:19 -08:00
blk-mq-virtio.c	blk-mq: initial support for multiple queue maps	2018-11-07 13:45:00 -07:00
blk-mq.c	block: don't lose track of REQ_INTEGRITY flag	2019-01-16 07:28:10 -07:00
blk-mq.h	blk-mq: fix dispatch from sw queue	2018-12-17 11:19:54 -07:00
blk-pm.c	block: remove the queue_lock indirection	2018-11-15 12:17:28 -07:00
blk-pm.h	block: remove the queue_lock indirection	2018-11-15 12:17:28 -07:00
blk-rq-qos.c	blk-mq-debugfs: support rq_qos	2018-12-16 19:53:47 -07:00
blk-rq-qos.h	block: fix blk-iolatency accounting underflow	2018-12-17 11:19:54 -07:00
blk-settings.c	SCSI misc on 20181224	2018-12-28 14:48:06 -08:00
blk-softirq.c	block: remove a few unused exports	2018-11-15 12:13:25 -07:00
blk-stat.c	block: remove a few unused exports	2018-11-15 12:13:25 -07:00
blk-stat.h	block: deactivate blk_stat timer in wbt_disable_default()	2018-12-12 06:47:51 -07:00
blk-sysfs.c	SCSI misc on 20181224	2018-12-28 14:48:06 -08:00
blk-throttle.c	blkcg: consolidate bio_issue_init() to be a part of core	2018-12-07 22:26:37 -07:00
blk-timeout.c	block: don't hold the queue_lock over blk_abort_request	2018-11-15 12:13:18 -07:00
blk-wbt.c	blk-wbt: Declare local functions static	2019-01-24 11:09:21 -07:00
blk-wbt.h	block: remove external dependency on wbt_flags	2018-07-09 09:07:54 -06:00
blk-zoned.c	for-4.21/block-20181221	2018-12-28 13:19:59 -08:00
blk.h	block: sum requests in the plug structure	2018-11-26 10:35:22 -07:00
bounce.c	blkcg: remove bio->bi_css and instead use bio->bi_blkg	2018-12-07 22:26:37 -07:00
bsg-lib.c	bsg: move bsg-lib parts outside of request queue	2018-11-07 13:42:33 -07:00
bsg.c	bsg: deprecate BIDI support in bsg	2018-12-21 08:47:58 -07:00
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
compat_ioctl.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	block: add queue_is_mq() helper	2018-11-16 08:34:06 -07:00
genhd.c	block: return just one value from part_in_flight	2018-12-10 08:30:38 -07:00
ioctl.c	block: Introduce BLKGETNRZONES ioctl	2018-10-25 11:17:40 -06:00
ioprio.c	block: add ioprio_check_cap function	2018-05-31 10:50:54 -04:00
kyber-iosched.c	kyber: use sbitmap add_wait_queue/list_del wait helpers	2018-12-20 12:17:21 -07:00
mq-deadline.c	block: mq-deadline: Fix write completion handling	2018-12-17 11:19:39 -07:00
opal_proto.h	block: sed-opal: Set MBRDone on S3 resume path if TPER is MBREnabled	2017-09-11 09:45:52 -06:00
partition-generic.c	block: return just one value from part_in_flight	2018-12-10 08:30:38 -07:00
scsi_ioctl.c	block: consistently use GFP_NOIO instead of __GFP_NORECLAIM	2018-05-14 08:55:18 -06:00
sed-opal.c	block: sed-opal: Fix a couple off by one bugs	2018-06-20 12:04:06 -06:00
t10-pi.c	block: move dif_prepare/dif_complete functions to block layer	2018-07-30 08:27:02 -06:00