linux_dsm_epyc7002/block
Paolo Valente 13c931bd9a block, bfq: update wr_busy_queues if needed on a queue split
This commit fixes a bug triggered by a non-trivial sequence of
events. These events are briefly described in the next two
paragraphs. The impatiens, or those who are familiar with queue
merging and splitting, can jump directly to the last paragraph.

On each I/O-request arrival for a shared bfq_queue, i.e., for a
bfq_queue that is the result of the merge of two or more bfq_queues,
BFQ checks whether the shared bfq_queue has become seeky (i.e., if too
many random I/O requests have arrived for the bfq_queue; if the device
is non rotational, then random requests must be also small for the
bfq_queue to be tagged as seeky). If the shared bfq_queue is actually
detected as seeky, then a split occurs: the bfq I/O context of the
process that has issued the request is redirected from the shared
bfq_queue to a new non-shared bfq_queue. As a degenerate case, if the
shared bfq_queue actually happens to be shared only by one process
(because of previous splits), then no new bfq_queue is created: the
state of the shared bfq_queue is just changed from shared to non
shared.

Regardless of whether a brand new non-shared bfq_queue is created, or
the pre-existing shared bfq_queue is just turned into a non-shared
bfq_queue, several parameters of the non-shared bfq_queue are set
(restored) to the original values they had when the bfq_queue
associated with the bfq I/O context of the process (that has just
issued an I/O request) was merged with the shared bfq_queue. One of
these parameters is the weight-raising state.

If, on the split of a shared bfq_queue,
1) a pre-existing shared bfq_queue is turned into a non-shared
bfq_queue;
2) the previously shared bfq_queue happens to be busy;
3) the weight-raising state of the previously shared bfq_queue happens
to change;
the number of weight-raised busy queues changes. The field
wr_busy_queues must then be updated accordingly, but such an update
was missing. This commit adds the missing update.

Reported-by: Luca Miccio <lucmiccio@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-27 12:30:47 -06:00
..
partitions partitions/ldm: switch to use uuid_t 2017-06-05 16:59:14 +02:00
badblocks.c block: Add fallthrough markers to switch statements 2017-06-21 11:46:07 -06:00
bfq-cgroup.c block, bfq: access and cache blkg data only when safe 2017-06-08 09:51:10 -06:00
bfq-iosched.c block, bfq: update wr_busy_queues if needed on a queue split 2017-06-27 12:30:47 -06:00
bfq-iosched.h block, bfq: access and cache blkg data only when safe 2017-06-08 09:51:10 -06:00
bfq-wf2q.c block, bfq: use pointer entity->sched_data only if set 2017-05-10 07:39:43 -06:00
bio-integrity.c Linux 4.12-rc5 2017-06-12 08:30:13 -06:00
bio.c block: add support for write hints in a bio 2017-06-27 12:05:27 -06:00
blk-cgroup.c block: Avoid that blk_exit_rl() triggers a use-after-free 2017-06-01 13:07:55 -06:00
blk-core.c block: don't set bounce limit in blk_init_queue 2017-06-27 12:13:45 -06:00
blk-exec.c block: introduce new block status code type 2017-06-09 09:27:32 -06:00
blk-flush.c block: Check locking assumptions at runtime 2017-06-20 19:27:14 -06:00
blk-integrity.c block: switch bios to blk_status_t 2017-06-09 09:27:32 -06:00
blk-ioc.c Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-03-03 10:53:35 -08:00
blk-lib.c block: remove the discard_zeroes_data flag 2017-04-08 11:25:38 -06:00
blk-map.c blk-map: call blk_queue_bounce from blk_rq_append_bio 2017-06-27 12:13:21 -06:00
blk-merge.c block: add support for write hints in a bio 2017-06-27 12:05:27 -06:00
blk-mq-cpumap.c blk-mq: export blk_mq_map_queues 2016-11-08 17:30:00 -05:00
blk-mq-debugfs.c blk-mq: expose write hints through debugfs 2017-06-27 12:05:31 -06:00
blk-mq-debugfs.h mq-deadline: add debugfs attributes 2017-05-04 08:25:17 -06:00
blk-mq-pci.c blk-mq-pci: Fix two spelling mistakes 2017-03-29 11:09:51 -06:00
blk-mq-sched.c Merge commit '8e8320c9315c' into for-4.13/block 2017-06-22 21:55:24 -06:00
blk-mq-sched.h Merge commit '8e8320c9315c' into for-4.13/block 2017-06-22 21:55:24 -06:00
blk-mq-sysfs.c blk-mq: untangle debugfs and sysfs 2017-05-04 08:24:13 -06:00
blk-mq-tag.c blk-mq: add shallow depth option for blk_mq_get_tag() 2017-04-14 14:06:54 -06:00
blk-mq-tag.h blk-mq-sched: Allocate sched reserved tags as specified in the original queue tagset 2017-03-02 08:56:04 -07:00
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 bounce by default 2017-06-27 12:13:45 -06:00
blk-mq.h blk-mq: remove __blk_mq_alloc_request 2017-06-18 10:08:55 -06:00
blk-settings.c block: don't bother with bounce limits for make_request drivers 2017-06-27 12:13:45 -06:00
blk-softirq.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/topology.h> 2017-03-02 08:42:26 +01:00
blk-stat.c blk-stat: don't use this_cpu_ptr() in a preemptable section 2017-05-10 07:40:18 -06:00
blk-stat.h blk-stat: kill blk_stat_rq_ddir() 2017-04-21 07:56:23 -06:00
blk-sysfs.c block: Fix a blk_exit_rl() regression 2017-06-14 13:27:50 -06:00
blk-tag.c block: Check locking assumptions at runtime 2017-06-20 19:27:14 -06:00
blk-throttle.c blk-throttle: set default latency baseline for harddisk 2017-06-07 09:09:32 -06:00
blk-timeout.c block: Check locking assumptions at runtime 2017-06-20 19:27:14 -06:00
blk-wbt.c blk-stat: kill blk_stat_rq_ddir() 2017-04-21 07:56:23 -06:00
blk-wbt.h block: Make writeback throttling defaults consistent for SQ devices 2017-04-19 08:49:03 -06:00
blk-zoned.c block: Rename blk_queue_zone_size and bdev_zone_size 2017-01-12 07:58:32 -07:00
blk.h block: move bounce declarations to block/blk.h 2017-06-27 12:13:45 -06:00
bounce.c block: remove the queue_bounce_pfn helper 2017-06-27 12:13:45 -06:00
bsg-lib.c block: introduce new block status code type 2017-06-09 09:27:32 -06:00
bsg.c block: Make most scsi_req_init() calls implicit 2017-06-20 19:27:14 -06:00
cfq-iosched.c Linux 4.12-rc5 2017-06-12 08:30:13 -06:00
cmdline-parser.c block: remove unrelated header files and export symbol 2014-01-21 20:18:26 -08:00
compat_ioctl.c block: remove the discard_zeroes_data flag 2017-04-08 11:25:38 -06:00
deadline-iosched.c block: enumify ELEVATOR_*_MERGE 2017-02-08 13:43:06 -07:00
elevator.c block: Add fallthrough markers to switch statements 2017-06-21 11:46:07 -06:00
genhd.c block: Constify disk_type 2017-06-20 19:27:14 -06:00
ioctl.c block: remove the discard_zeroes_data flag 2017-04-08 11:25:38 -06:00
ioprio.c block: Add fallthrough markers to switch statements 2017-06-21 11:46:07 -06:00
Kconfig Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 2017-05-12 15:43:10 -07:00
Kconfig.iosched block, bfq: add full hierarchical scheduling and cgroups support 2017-04-19 08:30:26 -06:00
kyber-iosched.c blk-mq-sched: unify request prepare methods 2017-06-18 10:08:55 -06:00
Makefile block, bfq: split bfq-iosched.c into multiple source files 2017-04-19 08:48:24 -06:00
mq-deadline.c mq-deadline: add debugfs attributes 2017-05-04 08:25:17 -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: allocate struct opal_dev dynamically 2017-02-17 12:41:47 -07:00
partition-generic.c block: fix an error code in add_partition() 2017-05-23 08:41:59 -06:00
scsi_ioctl.c block: Change argument type of scsi_req_init() 2017-06-20 19:27:14 -06:00
sed-opal.c block: sed-opal: Tone down all the pr_* to debugs 2017-04-07 14:24:16 -06:00
t10-pi.c block: Dedicated error code fixups 2017-06-16 09:47:15 -06:00