NeilBrown 2bc13b83e6 md: batch flush requests. ... Currently if many flush requests are submitted to an md device is quick succession, they are serialized and can take a long to process them all. We don't really need to call flush all those times - a single flush call can satisfy all requests submitted before it started. So keep track of when the current flush started and when it finished, allow any pending flush that was requested before the flush started to complete without waiting any more. Test results from Xiao: Test is done on a raid10 device which is created by 4 SSDs. The tool is dbench. 1. The latest linux stable kernel Operation Count AvgLat MaxLat -------------------------------------------------- Deltree 768 10.509 78.305 Flush 2078376 0.013 10.094 Close 21787697 0.019 18.821 LockX 96580 0.007 3.184 Mkdir 384 0.008 0.062 Rename 1255883 0.191 23.534 ReadX 46495589 0.020 14.230 WriteX 14790591 7.123 60.706 Unlink 5989118 0.440 54.551 UnlockX 96580 0.005 2.736 FIND_FIRST 10393845 0.042 12.079 SET_FILE_INFORMATION 2415558 0.129 10.088 QUERY_FILE_INFORMATION 4711725 0.005 8.462 QUERY_PATH_INFORMATION 26883327 0.032 21.715 QUERY_FS_INFORMATION 4929409 0.010 8.238 NTCreateX 29660080 0.100 53.268 Throughput 1034.88 MB/sec (sync open) 128 clients 128 procs max_latency=60.712 ms 2. With patch1 "Revert "MD: fix lock contention for flush bios"" Operation Count AvgLat MaxLat -------------------------------------------------- Deltree 256 8.326 36.761 Flush 693291 3.974 180.269 Close 7266404 0.009 36.929 LockX 32160 0.006 0.840 Mkdir 128 0.008 0.021 Rename 418755 0.063 29.945 ReadX 15498708 0.007 7.216 WriteX 4932310 22.482 267.928 Unlink 1997557 0.109 47.553 UnlockX 32160 0.004 1.110 FIND_FIRST 3465791 0.036 7.320 SET_FILE_INFORMATION 805825 0.015 1.561 QUERY_FILE_INFORMATION 1570950 0.005 2.403 QUERY_PATH_INFORMATION 8965483 0.013 14.277 QUERY_FS_INFORMATION 1643626 0.009 3.314 NTCreateX 9892174 0.061 41.278 Throughput 345.009 MB/sec (sync open) 128 clients 128 procs max_latency=267.939 m 3. With patch1 and patch2 Operation Count AvgLat MaxLat -------------------------------------------------- Deltree 768 9.570 54.588 Flush 2061354 0.666 15.102 Close 21604811 0.012 25.697 LockX 95770 0.007 1.424 Mkdir 384 0.008 0.053 Rename 1245411 0.096 12.263 ReadX 46103198 0.011 12.116 WriteX 14667988 7.375 60.069 Unlink 5938936 0.173 30.905 UnlockX 95770 0.005 4.147 FIND_FIRST 10306407 0.041 11.715 SET_FILE_INFORMATION 2395987 0.048 7.640 QUERY_FILE_INFORMATION 4672371 0.005 9.291 QUERY_PATH_INFORMATION 26656735 0.018 19.719 QUERY_FS_INFORMATION 4887940 0.010 7.654 NTCreateX 29410811 0.059 28.551 Throughput 1026.21 MB/sec (sync open) 128 clients 128 procs max_latency=60.075 ms Cc: <stable@vger.kernel.org> # v4.19+ Tested-by: Xiao Ni <xni@redhat.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>		2019-04-01 12:11:48 -06:00
..
accessibility
acpi	ACPI fix for 5.1-rc3	2019-03-30 10:09:11 -07:00
amba
android	binder: fix race between munmap() and direct reclaim	2019-03-21 06:51:32 +01:00
ata	libata: fix using DMA buffers on stack	2019-03-28 08:16:04 -06:00
atm
auxdisplay	auxdisplay: charlcd: make backlight initial state configurable	2019-03-17 08:48:45 +01:00
base	Device properties framework fix for 5.1-rc2	2019-03-22 12:08:52 -07:00
bcma
block	block: loop: mark bvec as ITER_BVEC_FLAG_NO_REF	2019-04-01 12:11:48 -06:00
bluetooth	Bluetooth: mediatek: add support for MediaTek MT7663U and MT7668U UART devices	2019-03-02 19:51:23 +01:00
bus	ARM: SoC driver updates for 5.1	2019-03-06 09:41:12 -08:00
cdrom
char	Merge branch 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2019-03-10 17:37:29 -07:00
clk	We have a fairly balanced mix of clk driver updates and clk framework	2019-03-14 08:46:17 -07:00
clocksource	clocksource/drivers/clps711x: Remove board support	2019-03-24 11:30:11 +01:00
connector	connector: fix unsafe usage of ->real_parent	2019-03-08 15:06:38 -08:00
cpufreq	cpufreq: scpi: Fix use after free	2019-03-28 11:14:31 +01:00
cpuidle	cpuidle: governor: Add new governors to cpuidle_governors again	2019-03-12 23:46:55 +01:00
crypto	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2019-03-13 09:51:17 -07:00
dax	device-dax for 5.1	2019-03-16 13:05:32 -07:00
dca
devfreq
dio
dma	dmaengine: stm32-mdma: Revert "dmaengine: stm32-mdma: Add a check on read_u32_array"	2019-03-25 21:56:54 +05:30
dma-buf
edac	Merge branch 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-03-08 09:11:39 -08:00
eisa
extcon
firewire
firmware	memblock: drop memblock_alloc_*_nopanic() variants	2019-03-12 10:04:02 -07:00
fmc
fpga
fsi
gnss
gpio	gpio fixes for v5.1-rc3	2019-03-29 03:04:47 +01:00
gpu	drm/i915 fixes for v5.2-rc3:	2019-03-29 10:45:11 +10:00
hid	Merge branch 'for-5.1/wacom' into for-linus	2019-03-05 15:43:05 +01:00
hsi
hv	Char/Misc driver patches for 5.1-rc1	2019-03-06 14:18:59 -08:00
hwmon
hwspinlock
hwtracing	ARM updates for 5.1-rc1	2019-03-15 14:37:46 -07:00
i2c	i2c: i801: Add support for Intel Comet Lake	2019-03-20 17:42:23 +01:00
i3c	- Add a /* fall-through */ comment in the dw-i3c-master driver	2019-03-04 19:05:02 -08:00
ide	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide	2019-03-11 09:34:00 -07:00
idle
iio	- New Drivers	2019-03-08 10:02:58 -08:00
infiniband	i40iw: Avoid panic when handling the inetdev event	2019-03-17 21:40:40 -03:00
input	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2019-03-11 10:57:11 -07:00
interconnect
iommu	Merge branch 'akpm' (patches from Andrew)	2019-03-29 16:02:28 -07:00
ipack
irqchip	irqchip/irq-mvebu-sei: Make mvebu_sei_ap806_caps static	2019-03-21 16:43:00 +01:00
isdn	mISDN: hfcpci: Test both vendor & device ID for Digium HFC4S	2019-03-18 18:32:44 -07:00
leds	leds: trigger: netdev: use memcpy in device_name_store	2019-03-30 19:09:32 +01:00
lightnvm	pblk: fix max_io calculation	2019-03-07 08:59:26 -07:00
macintosh	treewide: add checks for the return value of memblock_alloc*()	2019-03-12 10:04:02 -07:00
mailbox	mailbox: imx: keep MU irq working during suspend/resume	2019-03-11 02:51:43 -05:00
mcb
md	md: batch flush requests.	2019-04-01 12:11:48 -06:00
media	DMA mapping updates for 5.1	2019-03-10 11:54:48 -07:00
memory
memstick
message
mfd	DMA mapping updates for 5.1	2019-03-10 11:54:48 -07:00
misc	5.1 Merge Window Pull Request	2019-03-09 15:53:03 -08:00
mmc	mmc: renesas_sdhi: limit block count to 16 bit for old revisions	2019-03-21 11:41:46 +01:00
mtd	This pull request contains updates for both UBI and UBIFS:	2019-03-13 09:34:35 -07:00
mux
net	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2019-03-27 12:22:57 -07:00
nfc
ntb	Fixes for switchtec debugability and mapping table entries, NTB	2019-03-15 14:32:59 -07:00
nubus
nvdimm	device-dax for 5.1	2019-03-16 13:05:32 -07:00
nvme	nvmet: fix error flow during ns enable	2019-03-28 18:15:03 +01:00
nvmem	Char/Misc driver patches for 5.1-rc1	2019-03-06 14:18:59 -08:00
of	of: fix kmemleak crash caused by imbalance in early memory reservation	2019-03-12 10:04:02 -07:00
opp	PM / OPP: Update performance state when freq == old_freq	2019-03-12 09:45:56 +01:00
oprofile
parisc	DMA mapping updates for 5.1	2019-03-10 11:54:48 -07:00
parport	Revert "parport: daisy: use new parport device model"	2019-03-25 14:49:00 -07:00
pci	PCI/LINK: Deduplicate bandwidth reports for multi-function devices	2019-03-25 17:59:07 -05:00
pcmcia
perf	arm64 updates for 5.1:	2019-03-10 10:17:23 -07:00
phy	phy: sun4i-usb: Support set_mode to USB_HOST for non-OTG PHYs	2019-03-26 16:48:55 +09:00
pinctrl	This is the bulk of pin control changes for the v5.1 kernel cycle.	2019-03-11 11:12:50 -07:00
platform	Chrome Platform fixes for v5.1-rc2	2019-03-19 11:28:15 -07:00
pnp
power
powercap
pps
ps3
ptp	Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-03-05 14:08:26 -08:00
pwm	pwm: atmel: Remove useless symbolic definitions	2019-03-04 12:52:49 +01:00
rapidio	rapidio/mport_cdev: mark expected switch fall-through	2019-03-07 18:32:02 -08:00
ras
regulator	regulator: mc13xxx: Constify regulator_ops variables	2019-03-04 00:01:08 +00:00
remoteproc	remoteproc updates for v5.1	2019-03-14 09:00:06 -07:00
reset
rpmsg
rtc	chrome platform changes for v5.1	2019-03-12 09:46:32 -07:00
s390	SCSI fixes on 20190329	2019-03-29 14:58:49 -07:00
sbus
scsi	scsi: ibmvfc: Clean up transport events	2019-03-27 21:34:20 -04:00
sfi
sh
siox
slimbus
sn
soc	This pull request brings in a build fix for arm64 with bcm2835	2019-03-18 10:31:24 -07:00
soundwire
spi	pci-v5.1-changes	2019-03-09 14:57:08 -08:00
spmi
ssb
staging	staging: vt6655: Remove vif check from vnt_interrupt	2019-03-29 17:25:45 +01:00
target	SCSI misc on 20190315	2019-03-16 12:51:50 -07:00
tc
tee	ARM: SoC driver updates for 5.1	2019-03-06 09:41:12 -08:00
thermal	Merge branches 'fixes' and 'thermal-intel' into next	2019-03-18 22:37:44 +08:00
thunderbolt
tty	tty: fix NULL pointer issue when tty_port ops is not set	2019-03-28 01:21:21 +09:00
uio
usb	USB-serial fixes for 5.1-rc3	2019-03-29 15:31:16 +01:00
uwb
vfio	powerpc updates for 5.1	2019-03-07 12:56:26 -08:00
vhost	virtio: fixes, cleanups	2019-03-10 12:47:57 -07:00
video	fbdev changes for v5.1:	2019-03-15 14:22:59 -07:00
virt	virt: vbox: Implement passing requestor info to the host for VirtualBox 6.0.x	2019-03-28 01:55:18 +09:00
virtio	virtio: hint if callbacks surprisingly might sleep	2019-03-06 11:19:57 -05:00
visorbus
vlynq
vme
w1
watchdog	linux-watchdog 5.1-rc1 tag	2019-03-11 11:22:15 -07:00
xen	block: pass page to xen_biovec_phys_mergeable	2019-04-01 12:11:13 -06:00
zorro
Kconfig
Makefile	IOMMU Updates for Linux v5.1	2019-03-10 12:29:52 -07:00