Ming Lei e6fc464987 blk-mq: avoid starving tag allocation after allocating process migrates ... When the allocation process is scheduled back and the mapped hw queue is changed, fake one extra wake up on previous queue for compensating wake up miss, so other allocations on the previous queue won't be starved. This patch fixes one request allocation hang issue, which can be triggered easily in case of very low nr_request. The race is as follows: 1) 2 hw queues, nr_requests are 2, and wake_batch is one 2) there are 3 waiters on hw queue 0 3) two in-flight requests in hw queue 0 are completed, and only two waiters of 3 are waken up because of wake_batch, but both the two waiters can be scheduled to another CPU and cause to switch to hw queue 1 4) then the 3rd waiter will wait for ever, since no in-flight request is in hw queue 0 any more. 5) this patch fixes it by the fake wakeup when waiter is scheduled to another hw queue Cc: <stable@vger.kernel.org> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Modified commit message to make it clearer, and make it apply on top of the 4.18 branch. Signed-off-by: Jens Axboe <axboe@kernel.dk>		2018-05-24 11:00:39 -06:00
..
partitions	partitions/msdos: Unable to mount UFS 44bsd partitions	2018-01-10 09:12:16 -07:00
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
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
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	bfq-iosched: update shallow depth to smallest one used	2018-05-10 11:27:41 -06:00
bfq-iosched.h	bfq-iosched: remove unused variable	2018-05-10 11:27:31 -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	block: Export bio check/set pages_dirty	2018-05-14 13:16:15 -06:00
blk-cgroup.c	blkcg: init root blkcg_gq under lock	2018-04-19 08:51:59 -06:00
blk-core.c	block: Add warning for bi_next not NULL in bio_endio()	2018-05-14 13:16:13 -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	blk-mq: don't allocate driver tag upfront for flush rq	2017-11-04 12:40:13 -06:00
blk-integrity.c	block: switch bios to blk_status_t	2017-06-09 09:27:32 -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: consolidate struct request timestamp fields	2018-05-09 08:33:09 -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: remove blk_mq_delay_queue()	2018-04-10 08:38:46 -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-sched: Enable merging discard bio into request	2018-02-01 14:45:11 -07:00
blk-mq-sched.h	blk-mq-sched: remove unused 'can_block' arg from blk_mq_sched_insert_request	2018-01-17 09:49:21 -07:00
blk-mq-sysfs.c	block: properly protect the 'queue' kobj in blk_unregister_queue	2018-01-15 08:41:38 -07:00
blk-mq-tag.c	blk-mq: avoid starving tag allocation after allocating process migrates	2018-05-24 11:00:39 -06:00
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: remove wrong 'unlikely' check	2018-05-22 08:38:04 -06:00
blk-mq.h	blk-mq: fix sysfs inflight counter	2018-04-26 09:02:01 -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	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
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: Add sysfs entry for fua support	2018-05-14 13:16:17 -06:00
blk-tag.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
blk-throttle.c	block: get rid of struct blk_issue_stat	2018-05-09 08:33:05 -06:00
blk-timeout.c	blk-mq: Directly schedule q->timeout_work when aborting a request	2018-04-02 16:36:13 -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: consolidate struct request timestamp fields	2018-05-09 08:33:09 -06:00
bounce.c	block: don't disable interrupts during kmap_atomic()	2018-05-07 15:26:36 -06:00
bsg-lib.c	bsg: split handling of SCSI CDBs vs transport requeues	2018-03-13 11:40:24 -06:00
bsg.c	block: sanitize blk_get_request calling conventions	2018-05-14 08:55:12 -06:00
cfq-iosched.c	block: consolidate struct request timestamp fields	2018-05-09 08:33:09 -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	deadline-iosched: Introduce zone locking support	2018-01-05 09:22:17 -07:00
elevator.c	block: Document scheduler modification locking requirements	2018-01-18 12:54:42 -07:00
genhd.c	blk-mq: fix sysfs inflight counter	2018-04-26 09:02:01 -06:00
ioctl.c	block: pass inclusive 'lend' parameter to truncate_inode_pages_range	2018-02-23 15:20:19 -07:00
ioprio.c	block: Add fallthrough markers to switch statements	2017-06-21 11:46:07 -06:00
kyber-iosched.c	kyber-iosched: update shallow depth when setting up hardware queue	2018-05-10 11:27:46 -06:00
mq-deadline.c	mq-deadline: Make sure to always unlock zones	2018-03-01 08:39:24 -07:00
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	blk-mq: fix sysfs inflight counter	2018-04-26 09:02:01 -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	for-4.17/block-20180402	2018-04-05 14:27:02 -07:00
t10-pi.c	t10-pi: Move opencoded contants to common header	2017-07-03 16:56:25 -06:00