linux/block
Christoph Hellwig 4e68a01142 blk-mq: don't redistribute hardware queues on a CPU hotplug event
Currently blk-mq will totally remap hardware context when a CPU hotplug
even happened, which causes major havoc for drivers, as they are never
told about this remapping.  E.g. any carefully sorted out CPU affinity
will just be completely messed up.

The rebuild also doesn't really help for the common case of cpu
hotplug, which is soft onlining / offlining of cpus - in this case we
should just leave the queue and irq mapping as is.  If it actually
worked it would have helped in the case of physical cpu hotplug,
although for that we'd need a way to actually notify the driver.
Note that drivers may already be able to accommodate such a topology
change on their own, e.g. using the reset_controller sysfs file in NVMe
will cause the driver to get things right for this case.

With the rebuild removed we will simplify retain the queue mapping for
a soft offlined CPU that will work when it comes back online, and will
map any newly onlined CPU to queue 0 until the driver initiates
a rebuild of the queue map.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15 08:42:03 -06:00
..
partitions block: atari: Return early for unsupported sector size 2016-07-13 09:31:44 -07:00
badblocks.c block, badblocks: introduce devm_init_badblocks 2016-01-09 08:39:04 -08:00
bio-integrity.c block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
bio.c block: remove remnant refs to hardsect 2016-09-14 08:44:57 -06:00
blk-cgroup.c block/blk-cgroup.c: Declare local symbols static 2016-06-14 09:09:33 -06:00
blk-core.c block: add poll_considered statistic 2016-09-14 08:41:21 -06:00
blk-exec.c block: Fix spelling in a source code comment 2016-07-20 21:28:22 -06:00
blk-flush.c block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSH 2016-06-07 13:41:38 -06:00
blk-integrity.c block, libnvdimm, nvme: provide a built-in blk_integrity nop profile 2015-10-21 14:43:45 -06:00
blk-ioc.c mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd 2015-11-06 17:50:42 -08:00
blk-lib.c Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-block 2016-07-26 15:37:51 -07:00
blk-map.c block: simplify and export blk_rq_append_bio 2016-07-20 17:38:32 -06:00
blk-merge.c block: make sure a big bio is split into at most 256 bvecs 2016-08-24 08:17:24 -06:00
blk-mq-cpu.c
blk-mq-cpumap.c blk-mq: Avoid memoryless numa node encoded in hctx numa_node 2015-12-03 09:56:27 -07:00
blk-mq-sysfs.c block: enable zeroing of io_poll statistics 2016-09-14 08:41:23 -06:00
blk-mq-tag.c blk-mq: Introduce blk_mq_reinit_tagset 2016-07-08 08:38:49 -06:00
blk-mq-tag.h blk-mq: factor out a helper to iterate all tags for a request_queue 2015-10-01 10:10:57 +02:00
blk-mq.c blk-mq: don't redistribute hardware queues on a CPU hotplug event 2016-09-15 08:42:03 -06:00
blk-mq.h blk-mq: dynamic h/w context count 2016-02-09 12:42:17 -07:00
blk-settings.c block: kill off q->flush_flags 2016-04-13 13:33:19 -06:00
blk-softirq.c
blk-sysfs.c block: expose QUEUE_FLAG_DAX in sysfs 2016-07-20 21:01:08 -06:00
blk-tag.c block: support different tag allocation policy 2015-01-23 14:15:46 -07:00
blk-throttle.c block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
blk-timeout.c block: remove REQ_NO_TIMEOUT flag 2015-12-22 09:38:34 -07:00
blk.h block: simplify and export blk_rq_append_bio 2016-07-20 17:38:32 -06:00
bounce.c Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2015-09-19 18:57:09 -07:00
bsg-lib.c
bsg.c block: Simplify bsg complete all 2015-02-04 09:57:52 -07:00
cfq-iosched.c block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
cmdline-parser.c
compat_ioctl.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
deadline-iosched.c block: do not merge requests without consulting with io scheduler 2016-07-20 21:35:12 -06:00
elevator.c block: Fix secure erase 2016-08-16 09:16:51 -06:00
genhd.c block: fix bdi vs gendisk lifetime mismatch 2016-08-04 14:19:16 -06:00
ioctl.c DAX error handling for 4.7 2016-05-26 19:34:26 -07:00
ioprio.c block: fix use-after-free in sys_ioprio_get() 2016-07-01 08:39:24 -06:00
Kconfig block: remove BLK_DEV_DAX config option 2016-08-04 08:50:07 -04:00
Kconfig.iosched
Makefile Initial roundup of 4.5 merge window patches 2016-01-23 18:45:06 -08:00
noop-iosched.c elevator: use list_{first,prev,next}_entry 2015-11-16 15:21:48 -07:00
partition-generic.c block/partition-generic.c: Remove a set-but-not-used variable 2016-06-14 09:09:15 -06:00
scsi_ioctl.c mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM 2015-11-06 17:50:42 -08:00
t10-pi.c block: Consolidate static integrity profile properties 2015-10-21 14:42:38 -06:00