linux/block
Tejun Heo 2da8de0bb7 cfq-iosched: remove @gfp_mask from cfq_find_alloc_queue()
Even when allocations fail, cfq_find_alloc_queue() always returns a
valid cfq_queue by falling back to the oom cfq_queue.  As such, there
isn't much point in taking @gfp_mask and trying "harder" if __GFP_WAIT
is set.  GFP_NOWAIT allocations don't fail often and even when they do
the degraded behavior is acceptable and temporary.

After all, the only reason get_request(), which ultimately determines
the gfp_mask, cares about __GFP_WAIT is to guarantee request
allocation, assuming IO forward progress, for callers which are
willing to wait.  There's no reason for cfq_find_alloc_queue() to
behave differently on __GFP_WAIT when it already has a fallback
mechanism.

Remove @gfp_mask from cfq_find_alloc_queue() and propagate the changes
to its callers.  This simplifies the function quite a bit and will
help making async queues per-cfq_group.

v2: Updated to reflect GFP_ATOMIC -> GPF_NOWAIT.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-18 15:49:16 -07:00
..
partitions Merge branch 'for-3.20/core' of git://git.kernel.dk/linux-block 2015-02-12 14:13:23 -08:00
bio-integrity.c bio integrity: do not assume bio_integrity_pool exists if bioset exists 2015-07-07 07:46:47 -06:00
bio.c block: Do a full clone when splitting discard bios 2015-07-23 16:21:34 -06:00
blk-cgroup.c blkcg, cfq-iosched: use GFP_NOWAIT instead of GFP_ATOMIC for non-critical allocations 2015-08-18 15:49:16 -07:00
blk-core.c block: use FIELD_SIZEOF to calculate size of a field 2015-07-07 07:47:37 -06:00
blk-exec.c block: move PM request support to IDE 2015-05-05 13:40:42 -06:00
blk-flush.c blk-mq: support per-distpatch_queue flush machinery 2014-09-25 15:22:45 -06:00
blk-integrity.c writeback: separate out include/linux/backing-dev-defs.h 2015-06-02 08:33:34 -06:00
blk-ioc.c block: Substitute rcu_access_pointer() for rcu_dereference_raw() 2014-02-18 12:21:26 -08:00
blk-iopoll.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next 2014-06-03 12:57:53 -07:00
blk-lib.c block: Quiesce zeroout wrapper 2015-02-05 10:14:54 -07:00
blk-map.c blk_rq_map_user(): use import_single_range() 2015-04-11 22:27:13 -04:00
blk-merge.c block: only honor SG gap prevention for merges that contain data 2015-05-29 13:10:23 -06:00
blk-mq-cpu.c blk-mq: add file comments and update copyright notices 2014-05-28 10:15:41 -06:00
blk-mq-cpumap.c sched/topology: Rename topology_thread_cpumask() to topology_sibling_cpumask() 2015-05-27 15:22:15 +02:00
blk-mq-sysfs.c blk-mq: add blk_mq_init_allocated_queue and export blk_mq_register_disk 2015-03-13 08:26:53 -06:00
blk-mq-tag.c blk-mq: Shared tag enhancements 2015-06-01 14:35:56 -06:00
blk-mq-tag.h blk-mq: Shared tag enhancements 2015-06-01 14:35:56 -06:00
blk-mq.c blk-mq: set default timeout as 30 seconds 2015-07-16 08:39:11 -06:00
blk-mq.h blk-mq: release mq's kobjects in blk_release_queue() 2015-01-29 08:30:51 -08:00
blk-settings.c block: fix blk_stack_limits() regression due to lcm() change 2015-03-31 09:45:50 -06:00
blk-softirq.c block: fix regression with block enabled tagging 2014-04-09 21:54:06 -06:00
blk-sysfs.c Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block 2015-06-25 16:00:17 -07:00
blk-tag.c block: support different tag allocation policy 2015-01-23 14:15:46 -07:00
blk-throttle.c blkcg: move block/blk-cgroup.h to include/linux/blk-cgroup.h 2015-06-02 08:33:33 -06:00
blk-timeout.c blk-mq: Allow requests to never expire 2015-01-08 08:59:01 -07:00
blk.h blk-mq: make plug work for mutiple disks and queues 2015-05-08 14:17:23 -06:00
bounce.c Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block 2015-06-25 16:00:17 -07:00
bsg-lib.c bsg: Remove unused function bsg_goose_queue() 2012-12-06 14:33:02 +01:00
bsg.c block: Simplify bsg complete all 2015-02-04 09:57:52 -07:00
cfq-iosched.c cfq-iosched: remove @gfp_mask from cfq_find_alloc_queue() 2015-08-18 15:49:16 -07:00
cmdline-parser.c block: remove unrelated header files and export symbol 2014-01-21 20:18:26 -08:00
compat_ioctl.c block, bdi: an active gendisk always has a request_queue associated with it 2014-09-08 10:00:35 -06:00
deadline-iosched.c block: Stop abusing csd.list for fifo_time 2014-02-24 14:46:32 -08:00
elevator.c Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block 2015-06-25 16:00:17 -07:00
genhd.c Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block 2015-06-25 16:00:17 -07:00
ioctl.c block: replace trylock with mutex_lock in blkdev_reread_part() 2015-05-20 09:05:45 -06:00
ioprio.c block: Fix computation of merged request priority 2014-10-31 08:30:43 -06:00
Kconfig block: Add T10 Protection Information functions 2014-09-27 09:14:59 -06:00
Kconfig.iosched blkcg: make CONFIG_BLK_CGROUP bool 2012-03-06 21:27:21 +01:00
Makefile block: Add T10 Protection Information functions 2014-09-27 09:14:59 -06:00
noop-iosched.c elevator: Fix a race in elevator switching 2013-07-03 13:25:24 +02:00
partition-generic.c block: Fix dev_t minor allocation lifetime 2014-09-03 15:01:02 -06:00
scsi_ioctl.c block: fix bogus EFAULT error from SG_IO ioctl 2015-06-27 11:43:34 -06:00
t10-pi.c block: Add T10 Protection Information functions 2014-09-27 09:14:59 -06:00