linux_dsm_epyc7002/drivers
Ming Lei b5dd2f6047 block: loop: improve performance via blk-mq
The conversion is a bit straightforward, and use work queue to
dispatch requests of loop block, and one big change is that requests
is submitted to backend file/device concurrently with work queue,
so throughput may get improved much. Given write requests over same
file are often run exclusively, so don't handle them concurrently for
avoiding extra context switch cost, possible lock contention and work
schedule cost. Also with blk-mq, there is opportunity to get loop I/O
merged before submitting to backend file/device.

In the following test:
	- base: v3.19-rc2-2041231
	- loop over file in ext4 file system on SSD disk
	- bs: 4k, libaio, io depth: 64, O_DIRECT, num of jobs: 1
	- throughput: IOPS

	------------------------------------------------------
	|            | base      | base with loop-mq | delta |
	------------------------------------------------------
	| randread   | 1740      | 25318             | +1355%|
	------------------------------------------------------
	| read       | 42196     | 51771             | +22.6%|
	-----------------------------------------------------
	| randwrite  | 35709     | 34624             | -3%   |
	-----------------------------------------------------
	| write      | 39137     | 40326             | +3%   |
	-----------------------------------------------------

So loop-mq can improve throughput for both read and randread, meantime,
performance of write and randwrite isn't hurted basically.

Another benefit is that loop driver code gets simplified
much after blk-mq conversion, and the patch can be thought as
cleanup too.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-02 15:07:49 -07:00
..
accessibility
acpi Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-19 14:02:02 -08:00
amba Char/Misc driver patches for 3.19-rc1 2014-12-14 16:43:47 -08:00
android
ata More ACPI and power management updates for 3.19-rc1 2014-12-18 20:28:33 -08:00
atm Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
auxdisplay
base More ACPI and power management updates for 3.19-rc1 2014-12-18 20:28:33 -08:00
bcma Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2014-12-11 17:56:37 -08:00
block block: loop: improve performance via blk-mq 2015-01-02 15:07:49 -07:00
bluetooth Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next 2014-12-15 13:23:09 -05:00
bus Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
cdrom
char Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux 2014-12-25 16:04:15 -08:00
clk Please consider pulling the clk framework changes toward 3.19. It is 2014-12-20 16:42:36 -08:00
clocksource Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2014-12-11 17:56:37 -08:00
connector
coresight
cpufreq Update/Remove soon-to-be-dead email address 2014-12-19 12:56:15 -08:00
cpuidle powerpc updates for 3.19 batch 2 2014-12-19 12:57:45 -08:00
crypto Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
dca
devfreq
dio
dma Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
dma-buf
edac Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
eisa
extcon Char/Misc driver patches for 3.19-rc1 2014-12-14 16:43:47 -08:00
firewire firewire: sbp2: replace card lock by target lock 2014-12-10 20:53:21 +01:00
firmware Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
fmc
gpio Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
gpu Revert "drm/gem: Warn on illegal use of the dumb buffer interface v2" 2014-12-24 13:13:22 +10:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2014-12-12 10:26:47 -08:00
hsi * misc. fixes in omap-ssi and nokia-modem drivers 2014-12-15 17:33:47 -08:00
hv Char/Misc driver patches for 3.19-rc1 2014-12-14 16:43:47 -08:00
hwmon Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2014-12-17 10:16:27 -08:00
hwspinlock
i2c Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2014-12-20 13:52:52 -08:00
ide Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
idle
iio Staging patches for 3.19-rc1 2014-12-15 18:06:13 -08:00
infiniband SCSI for-linus on 20141220 2014-12-20 13:42:57 -08:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2014-12-17 10:06:02 -08:00
iommu Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-19 14:02:02 -08:00
ipack
irqchip Merge branch 'irq-irqdomain-arm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-15 17:30:09 -08:00
isdn Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2014-12-12 10:08:06 -08:00
leds More ACPI and power management updates for 3.19-rc1 2014-12-18 20:28:33 -08:00
lguest virtio: allow finalize_features to fail 2014-12-09 16:32:32 +02:00
macintosh macintosh: therm_pm72: delete deprecated driver 2014-12-19 19:32:47 +01:00
mailbox Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
mcb
md dm: fix missed error code if .end_io isn't implemented by target_type 2014-12-17 12:31:13 -05:00
media More ACPI and power management updates for 3.19-rc1 2014-12-18 20:28:33 -08:00
memory MTD updates for 3.19: 2014-12-17 09:59:26 -08:00
memstick
message
mfd Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
misc powerpc updates for 3.19 batch 2 2014-12-19 12:57:45 -08:00
mmc More ACPI and power management updates for 3.19-rc1 2014-12-18 20:28:33 -08:00
mtd MTD updates for 3.19: 2014-12-17 09:59:26 -08:00
net Main batch of InfiniBand/RDMA changes for 3.19: 2014-12-18 20:10:44 -08:00
nfc More ACPI and power management updates for 3.19-rc1 2014-12-18 20:28:33 -08:00
ntb
nubus
of ARM: SoC/iommu configuration for 3.19 2014-12-16 14:53:01 -08:00
oprofile
parisc
parport Char/Misc driver patches for 3.19-rc1 2014-12-14 16:43:47 -08:00
pci Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-19 14:02:02 -08:00
pcmcia Char/Misc driver patches for 3.19-rc1 2014-12-14 16:43:47 -08:00
phy More ACPI and power management updates for 3.19-rc1 2014-12-18 20:28:33 -08:00
pinctrl Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
platform platform-drivers-x86 for 3.19 2014-12-18 20:24:55 -08:00
pnp
power More ACPI and power management updates for 3.19-rc1 2014-12-18 20:28:33 -08:00
powercap
pps
ps3
ptp
pwm pwm: Changes for v3.19-rc1 2014-12-17 10:10:51 -08:00
rapidio
ras
regulator Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
remoteproc Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
reset Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
rpmsg
rtc Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
s390 Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
sbus
scsi SCSI for-linus on 20141220 2014-12-20 13:42:57 -08:00
sfi
sh drivers: sh / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM 2014-12-05 03:08:24 +01:00
sn
soc Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2014-12-15 15:52:01 -08:00
spi spi: Replace CONFIG_PM_RUNTIME with CONFIG_PM 2014-12-19 15:25:31 +01:00
spmi
ssb Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2014-12-11 17:56:37 -08:00
staging [regression] braino in "lustre: use is_root_inode()" 2014-12-26 22:43:19 -05:00
target SCSI for-linus on 20141220 2014-12-20 13:42:57 -08:00
tc
thermal Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-19 13:29:20 -08:00
thunderbolt
tty tty: 8250_omap: Replace CONFIG_PM_RUNTIME with CONFIG_PM 2014-12-19 15:27:58 +01:00
uio Char/Misc driver patches for 3.19-rc1 2014-12-14 16:43:47 -08:00
usb SCSI for-linus on 20141220 2014-12-20 13:42:57 -08:00
uwb
vfio VFIO updates for v3.19-rc1 2014-12-17 10:44:22 -08:00
vhost vhost/virtio: virtio 1.0 related fixes 2014-12-18 20:50:30 -08:00
video More ACPI and power management updates for 3.19-rc1 2014-12-18 20:28:33 -08:00
virt
virtio vhost/virtio: virtio 1.0 related fixes 2014-12-18 20:50:30 -08:00
vlynq
vme
w1 Char/Misc driver patches for 3.19-rc1 2014-12-14 16:43:47 -08:00
watchdog watchdog: imx2_wdt: Fix the argument of watchdog_active() 2014-12-18 16:01:20 +01:00
xen Merge remote-tracking branch 'scsi-queue/drivers-for-3.19' into for-linus 2014-12-18 05:56:29 -08:00
zorro
Kconfig Staging patches for 3.19-rc1 2014-12-15 18:06:13 -08:00
Makefile Staging patches for 3.19-rc1 2014-12-15 18:06:13 -08:00