Jens Axboe 1f57f8d442 blk-mq: don't queue more if we get a busy return ... Some devices have different queue limits depending on the type of IO. A classic case is SATA NCQ, where some commands can queue, but others cannot. If we have NCQ commands inflight and encounter a non-queueable command, the driver returns busy. Currently we attempt to dispatch more from the scheduler, if we were able to queue some commands. But for the case where we ended up stopping due to BUSY, we should not attempt to retrieve more from the scheduler. If we do, we can get into a situation where we attempt to queue a non-queueable command, get BUSY, then successfully retrieve more commands from that scheduler and queue those. This can repeat forever, starving the non-queuable command indefinitely. Fix this by NOT attempting to pull more commands from the scheduler, if we get a BUSY return. This should also be more optimal in terms of letting requests stay in the scheduler for as long as possible, if we get a BUSY due to the regular out-of-tags condition. Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>		2018-06-29 07:52:31 -06:00
..
partitions	block: add verifier for cmdline partition	2018-06-05 09:20:53 -06:00
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	block: use ktime_get_ns() instead of sched_clock() for cfq and bfq	2018-05-09 08:33:06 -06:00
bfq-iosched.c	block, bfq: prevent soft_rt_next_start from being stuck at infinity	2018-05-31 08:54:41 -06:00
bfq-iosched.h	block, bfq: remove slow-system class	2018-05-31 08:54:38 -06:00
bfq-wf2q.c	block, bfq: limit sectors served with interactive weight raising	2018-01-18 08:21:37 -07:00
bio-integrity.c	block: Convert bio_set to mempool_init()	2018-05-14 13:16:03 -06:00
bio.c	Revert "block: Add warning for bi_next not NULL in bio_endio()"	2018-06-19 11:59:47 -06:00
blk-cgroup.c	blkcg: init root blkcg_gq under lock	2018-04-19 08:51:59 -06:00
blk-core.c	block: Fix cloning of requests with a special payload	2018-06-28 09:51:30 -06:00
blk-exec.c	blk-mq-sched: remove unused 'can_block' arg from blk_mq_sched_insert_request	2018-01-17 09:49:21 -07:00
blk-flush.c	block: fix use-after-free in block flush handling	2018-06-09 06:37:14 -06:00
blk-integrity.c	block drivers/block: Use octal not symbolic permissions	2018-05-24 13:38:59 -06:00
blk-ioc.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
blk-lib.c	block: break discard submissions into the user defined size	2018-05-08 15:10:44 -06:00
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	block: don't use blocking queue entered for recursive bio submits	2018-06-02 20:35:00 -06:00
blk-mq-cpumap.c	blk-mq: don't keep offline CPUs mapped to hctx 0	2018-04-10 08:38:46 -06:00
blk-mq-debugfs.c	blk-mq-debugfs: Off by one in blk_mq_rq_state_name()	2018-06-20 11:26:04 -06:00
blk-mq-debugfs.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
blk-mq-pci.c	blk-mq: Allow PCI vector offset for mapping queues	2018-03-27 21:25:36 -06:00
blk-mq-rdma.c	block: Add rdma affinity based queue mapping helper	2017-08-08 14:58:03 -04:00
blk-mq-sched.c	blk-mq: update nr_requests when switching to 'none' scheduler	2018-06-02 20:35:00 -06:00
blk-mq-sched.h	block: move sysfs_lock into elevator_init	2018-06-01 07:38:19 -06:00
blk-mq-sysfs.c	block drivers/block: Use octal not symbolic permissions	2018-05-24 13:38:59 -06:00
blk-mq-tag.c	blk-mq: remove blk_mq_tagset_iter	2018-06-14 17:01:45 +02:00
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: provide a default queue mapping for virtio device	2017-02-27 20:54:05 +02:00
blk-mq.c	blk-mq: don't queue more if we get a busy return	2018-06-29 07:52:31 -06:00
blk-mq.h	blk-mq: Remove generation seqeunce	2018-05-29 08:59:21 -06:00
blk-settings.c	block: Introduce blk_queue_flag_{set,clear,test_and_{set,clear}}()	2018-03-08 14:13:48 -07:00
blk-softirq.c	block: fix timeout changes for legacy request drivers	2018-06-19 11:27:18 -06:00
blk-stat.c	block: consolidate struct request timestamp fields	2018-05-09 08:33:09 -06:00
blk-stat.h	block: consolidate struct request timestamp fields	2018-05-09 08:33:09 -06:00
blk-sysfs.c	block: convert bounce, q->bio_split to bioset_init()/mempool_init()	2018-05-30 15:33:32 -06:00
blk-tag.c	block: remov blk_queue_invalidate_tags	2018-06-15 08:13:35 -06:00
blk-throttle.c	blk-throttle: return proper bool type to caller instead of 0/1	2018-05-30 12:48:22 -06:00
blk-timeout.c	blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONE	2018-06-23 10:25:45 -06:00
blk-wbt.c	block: get rid of struct blk_issue_stat	2018-05-09 08:33:05 -06:00
blk-wbt.h	block: get rid of struct blk_issue_stat	2018-05-09 08:33:05 -06:00
blk-zoned.c	blkdev_report_zones_ioctl(): Use vmalloc() to allocate large buffers	2018-05-22 11:58:07 -06:00
blk.h	block: split the blk-mq case from elevator_init	2018-06-01 07:38:21 -06:00
bounce.c	block: fixup bioset_integrity_create() call	2018-05-30 18:51:21 -06:00
bsg-lib.c	block: remove parent device reference from struct bsg_class_device	2018-05-29 13:00:25 -06:00
bsg.c	bsg: fix race of bsg_open and bsg_unregister	2018-06-15 08:15:37 -06:00
cfq-iosched.c	block drivers/block: Use octal not symbolic permissions	2018-05-24 13:38:59 -06:00
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
deadline-iosched.c	block drivers/block: Use octal not symbolic permissions	2018-05-24 13:38:59 -06:00
elevator.c	block: split the blk-mq case from elevator_init	2018-06-01 07:38:21 -06:00
genhd.c	Merge branch 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2018-06-04 10:00:01 -07:00
ioctl.c	block: pass inclusive 'lend' parameter to truncate_inode_pages_range	2018-02-23 15:20:19 -07:00
ioprio.c	block: add ioprio_check_cap function	2018-05-31 10:50:54 -04:00
Kconfig	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
Kconfig.iosched	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
kyber-iosched.c	block: kyber: make kyber more friendly with merging	2018-05-30 10:47:40 -06:00
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
mq-deadline.c	block drivers/block: Use octal not symbolic permissions	2018-05-24 13:38:59 -06:00
noop-iosched.c	block: move existing elevator ops to union	2017-01-17 10:03:33 -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: don't print a message when the device went away	2018-05-29 08:59:21 -06:00
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	t10-pi: Move opencoded contants to common header	2017-07-03 16:56:25 -06:00