Omar Sandoval da55f2cc78 blk-mq: use sbq wait queues instead of restart for driver tags ... Commit 50e1dab86a ("blk-mq-sched: fix starvation for multiple hardware queues and shared tags") fixed one starvation issue for shared tags. However, we can still get into a situation where we fail to allocate a tag because all tags are allocated but we don't have any pending requests on any hardware queue. One solution for this would be to restart all queues that share a tag map, but that really sucks. Ideally, we could just block and wait for a tag, but that isn't always possible from blk_mq_dispatch_rq_list(). However, we can still use the struct sbitmap_queue wait queues with a custom callback instead of blocking. This has a few benefits: 1. It avoids iterating over all hardware queues when completing an I/O, which the current restart code has to do. 2. It benefits from the existing rolling wakeup code. 3. It avoids punting to another thread just to have it block. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>		2017-02-23 11:55:46 -07:00
..
acpi	Merge branches 'acpi-bus', 'acpi-sleep' and 'acpi-processor'	2017-02-20 14:28:03 +01:00
asm-generic	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-02-20 13:23:30 -08:00
clocksource
crypto	This pull contains one set of changes: a conversion of the crypto DocBook	2016-12-17 16:00:34 -08:00
drm	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-02-20 13:23:30 -08:00
dt-bindings	hwmon updates for v4.11	2017-02-20 09:52:08 -08:00
keys
kvm	KVM: arm64: Access CNTHCTL_EL2 bit fields correctly on VHE systems	2017-01-13 11:19:25 +00:00
linux	blk-mq: use sbq wait queues instead of restart for driver tags	2017-02-23 11:55:46 -07:00
math-emu
media
memory
misc
net	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-02-20 13:23:30 -08:00
pcmcia
ras
rdma	RDMA/core: Add the function ib_mtu_int_to_enum	2017-01-24 15:34:22 -05:00
rxrpc
scsi	block: introduce blk_rq_is_passthrough	2017-01-31 14:00:34 -07:00
soc	power supply and reset changes for the v4.11 series	2017-02-20 10:00:10 -08:00
sound	Merge remote-tracking branches 'asoc/fix/arizona', 'asoc/fix/dpcm', 'asoc/fix/dwc', 'asoc/fix/fsl-ssi' and 'asoc/fix/hdmi-codec' into asoc-linus	2017-01-10 10:47:50 +00:00
target	target: Fix multi-session dynamic se_node_acl double free OOPs	2017-02-08 08:25:23 -08:00
trace	for-4.11/linus-merge-signed	2017-02-21 10:57:33 -08:00
uapi	Merge branch 'for-4.11/block' into for-4.11/linus-merge	2017-02-17 14:06:45 -07:00
video
xen
Kbuild