Luca Miccio a33801e8b4 block, bfq: move debug blkio stats behind CONFIG_DEBUG_BLK_CGROUP ... BFQ currently creates, and updates, its own instance of the whole set of blkio statistics that cfq creates. Yet, from the comments of Tejun Heo in [1], it turned out that most of these statistics are meant/useful only for debugging. This commit makes BFQ create the latter, debugging statistics only if the option CONFIG_DEBUG_BLK_CGROUP is set. By doing so, this commit also enables BFQ to enjoy a high perfomance boost. The reason is that, if CONFIG_DEBUG_BLK_CGROUP is not set, then BFQ has to update far fewer statistics, and, in particular, not the heaviest to update. To give an idea of the benefits, if CONFIG_DEBUG_BLK_CGROUP is not set, then, on an Intel i7-4850HQ, and with 8 threads doing random I/O in parallel on null_blk (configured with 0 latency), the throughput of BFQ grows from 310 to 400 KIOPS (+30%). We have measured similar or even much higher boosts with other CPUs: e.g., +45% with an ARM CortexTM-A53 Octa-core. Our results have been obtained and can be reproduced very easily with the script in [1]. [1] https://www.spinics.net/lists/linux-block/msg18943.html Suggested-by: Tejun Heo <tj@kernel.org> Suggested-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Lee Tibbert <lee.tibbert@gmail.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Luca Miccio <lucmiccio@gmail.com> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>		2017-11-14 20:13:33 -07:00
..
ABI	This is the bulk of GPIO changes for the v4.15 kernel cycle:	2017-11-14 17:23:44 -08:00
accounting
acpi	ACPI / LPIT: Add Low Power Idle Table (LPIT) support	2017-10-11 15:38:10 +02:00
admin-guide	Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-11-13 17:33:11 -08:00
aoe
arm	Documentation: arm: Replace use of virt_to_phys with __pa_symbol	2017-07-17 13:43:58 -06:00
arm64	irqchip/gic-v3-its: Workaround HiSilicon Hip07 redistributor addressing	2017-10-19 11:22:40 +01:00
auxdisplay
backlight
blackfin
block	block, bfq: move debug blkio stats behind CONFIG_DEBUG_BLK_CGROUP	2017-11-14 20:13:33 -07:00
blockdev	SCSI misc on 20170907	2017-09-07 21:11:05 -07:00
bus-devices
cdrom	documentation: Update ide-cd documentation to reflect CONFIG_BLK_DEV_HD_IDE removal	2017-10-12 11:25:31 -06:00
cgroup-v1	mm, vmpressure: pass-through notification support	2017-07-10 16:32:31 -07:00
cma
connector
console
core-api	A relatively calm cycle for the docs tree again.	2017-11-13 08:25:06 -08:00
cpu-freq	cpufreq: stats: Handle the case when trans_table goes beyond PAGE_SIZE	2017-11-08 23:41:25 +01:00
cpuidle
cris
crypto	crypto: doc - adapt api sample to use async. op wait	2017-11-03 22:11:23 +08:00
dev-tools	docs: dev-tools: correct Coccinelle version number	2017-10-19 12:55:24 -06:00
device-mapper	dm raid: fix incorrect status output at the end of a "recover" process	2017-10-05 16:21:30 -04:00
devicetree	DeviceTree for 4.15:	2017-11-14 18:25:40 -08:00
doc-guide	Documentation: fix ref to sphinx/kerneldoc.py	2017-10-19 12:57:10 -06:00
driver-api	SCSI misc on 20171114	2017-11-14 16:23:44 -08:00
driver-model	driver core: remove DRIVER_ATTR	2017-09-19 09:20:33 +02:00
early-userspace
EDID
extcon
fault-injection	cpu/hotplug: Get rid of CPU hotplug notifier leftovers	2017-11-13 10:03:53 +01:00
fb	documentation: fb: update list of available compiled-in fonts	2017-11-08 03:39:52 -07:00
features	Documentation/features/KASAN: mark KASAN as supported only on 64-bit on x86	2017-10-03 14:40:22 -06:00
filesystems	Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs	2017-11-14 14:13:11 -08:00
firmware_class
fmc
fpga
frv
gpio	gpio: Move irq_valid_mask into struct gpio_irq_chip	2017-11-08 14:10:18 +01:00
gpu	Merge tag 'drm-intel-next-2017-08-18' of git://anongit.freedesktop.org/git/drm-intel into drm-next	2017-08-22 10:03:07 +10:00
hid	Documentation: fix input related doc refs	2017-10-12 11:14:06 -06:00
hwmon	pmbus: Add driver for Maxim MAX31785 Intelligent Fan Controller	2017-11-05 06:06:33 -08:00
i2c	i2c: i801: Add support for Intel Cedar Fork	2017-10-05 14:44:56 +02:00
ia64
ide
iio	iio: adc: New driver for Cirrus Logic EP93xx ADC	2017-07-25 19:56:23 +01:00
infiniband	Documentation: Hardware tag matching	2017-08-29 08:30:21 -04:00
input	Documentation: fix input related doc refs	2017-10-12 11:14:06 -06:00
ioctl	scsi: cxlflash: Introduce host ioctl support	2017-06-26 15:01:11 -04:00
isdn
kbuild	DeviceTree for 4.15:	2017-11-14 18:25:40 -08:00
kdump	kexec/kdump: minor Documentation updates for arm64 and Image	2017-07-12 16:26:00 -07:00
kernel-hacking	There has been a fair amount of activity in the docs tree this time	2017-07-03 21:13:25 -07:00
laptops	Documentation: fix admin-guide doc refs	2017-10-12 11:13:28 -06:00
leds	Documentation: leds: Update 00-INDEX file	2017-10-23 20:17:03 +02:00
lightnvm	lightnvm: physical block device (pblk) target	2017-04-16 10:06:33 -06:00
livepatch
locking	Documentation: fix locking rt-mutex doc refs	2017-10-19 12:56:44 -06:00
m68k
md	md-cluster: update document for raid10	2017-11-01 21:32:25 -07:00
media	Documentation: fix media related doc refs	2017-10-12 11:15:06 -06:00
memory-devices
metag
mic
mips
misc-devices	Documentation: misc-devices: Add Documentation for pci-endpoint-test driver	2017-04-28 10:23:19 -05:00
mmc	MMC core:	2017-05-02 17:34:32 -07:00
mn10300
mtd
namespaces
netlabel
networking	A relatively calm cycle for the docs tree again.	2017-11-13 08:25:06 -08:00
nfc
nios2
nvdimm
nvmem	NVMEM documentation fix: A minor typo	2017-08-24 13:31:58 -06:00
openrisc	Documentation: openrisc: Updates to README	2017-10-30 21:37:53 +09:00
parisc
PCI	docs: update old references for DocBook from the documentation	2017-05-16 08:44:19 -03:00
pcmcia
perf
phy
platform
power	Power management updates for v4.15-rc1	2017-11-13 19:43:50 -08:00
powerpc	powerpc updates for 4.13	2017-07-07 13:55:45 -07:00
pps	drivers/pps: aesthetic tweaks to PPS-related content	2017-09-08 18:26:51 -07:00
process	A relatively calm cycle for the docs tree again.	2017-11-13 08:25:06 -08:00
pti
ptp
rapidio
RCU	Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-11-13 12:18:10 -08:00
s390
scheduler	sched/deadline: Add documentation about GRUB reclaiming	2017-06-08 10:31:56 +02:00
scsi	scsi: smartpqi: correct spelling error in documentation	2017-10-23 04:15:17 -04:00
security	Documentation: fix security related doc refs	2017-10-12 11:14:40 -06:00
serial	tty: n_gsm: do not send/receive in ldisc close path	2017-06-03 18:48:52 +09:00
sh	docs-rst: convert sh book to ReST	2017-05-16 08:44:18 -03:00
sound	sound updates for 4.15-rc1	2017-11-14 18:01:46 -08:00
sparc
sphinx	Documentation/sphinx: fix kernel-doc decode for non-utf-8 locale	2017-08-31 13:36:28 -06:00
sphinx-static	docs RTD theme: code-block with line nos - lines and line numbers don't line up.	2017-07-17 13:48:45 -06:00
spi	spi: Document SPI slave controller support	2017-05-26 13:11:00 +01:00
sysctl	docs: Update binfmt_misc links	2017-10-03 15:23:38 -06:00
target	Documentation/target: add an example script to configure an iSCSI target	2017-05-01 22:21:35 -07:00
thermal	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux	2017-05-12 11:58:45 -07:00
timers	docs: highres: fix broken urls	2017-09-26 14:58:23 -06:00
trace	ftrace/docs: Add documentation on how to use ftrace from within the kernel	2017-11-05 09:55:29 -07:00
translations	locking/barriers: Kill lockless_dereference()	2017-10-24 13:17:33 +02:00
usb	Documentation: fix usb related doc refs	2017-10-12 11:15:48 -06:00
userspace-api	seccomp: Implement SECCOMP_RET_KILL_PROCESS action	2017-08-14 13:46:50 -07:00
virtual	KVM/ARM Changes for v4.14	2017-09-07 18:22:04 +02:00
vm	hmm: heterogeneous memory management documentation	2017-09-08 18:26:45 -07:00
w1
watchdog	Documentation: fix selftests related file refs	2017-10-19 12:58:21 -06:00
wimax
x86	Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-11-13 19:05:19 -08:00
xtensa	of: update ePAPR references to point to Devicetree Specification	2017-06-22 11:22:06 -05:00
.gitignore
00-INDEX	linux-kselftest-4.13-rc1-update	2017-07-07 14:04:47 -07:00
atomic_bitops.txt	Documentation/locking/atomic: Add documents for new atomic_t APIs	2017-08-10 12:29:00 +02:00
atomic_t.txt	Documentation/locking/atomic: Finish the document...	2017-08-25 11:06:33 +02:00
bcache.txt	bcache.txt: standardize document format	2017-07-14 13:51:27 -06:00
bt8xxgpio.txt	bt8xxgpio.txt: standardize document format	2017-07-14 13:51:27 -06:00
btmrvl.txt	btmrvl.txt: standardize document format	2017-07-14 13:51:27 -06:00
bus-virt-phys-mapping.txt	bus-virt-phys-mapping.txt: standardize document format	2017-07-14 13:51:28 -06:00
cachetlb.txt	cachetlb.txt: standardize document format	2017-07-14 13:51:28 -06:00
cgroup-v2.txt	cgroup: add cgroup.stat interface with basic hierarchy stats	2017-08-02 12:05:20 -07:00
Changes
circular-buffers.txt	circular-buffers.txt: standardize document format	2017-07-14 13:51:29 -06:00
clk.txt	clk.txt: standardize document format	2017-07-14 13:51:29 -06:00
CodingStyle
conf.py	docs-rst: don't require adjustbox anymore	2017-09-08 10:02:55 -06:00
cpu-load.txt	cpu-load: standardize document format	2017-07-14 13:51:30 -06:00
cputopology.txt	cputopology.txt: standardize document format	2017-07-14 13:51:30 -06:00
crc32.txt	crc32.txt: standardize document format	2017-07-14 13:51:30 -06:00
dcdbas.txt	dcdbas.txt: standardize document format	2017-07-14 13:51:31 -06:00
debugging-modules.txt
debugging-via-ohci1394.txt	debugging-via-ohci1394.txt: standardize document format	2017-07-14 13:51:34 -06:00
dell_rbu.txt	dell_rbu.txt: standardize document format	2017-07-14 13:58:12 -06:00
digsig.txt	digsig.txt: standardize document format	2017-07-14 13:51:31 -06:00
DMA-API-HOWTO.txt	DMA-API-HOWTO.txt: standardize document format	2017-07-14 13:51:32 -06:00
DMA-API.txt	dma-coherent: remove the DMA_MEMORY_MAP and DMA_MEMORY_IO flags	2017-09-01 11:59:17 +02:00
DMA-attributes.txt	DMA-attributes.txt: standardize document format	2017-07-14 13:51:33 -06:00
DMA-ISA-LPC.txt	DMA-ISA-LPC.txt: standardize document format	2017-07-14 13:51:33 -06:00
docutils.conf
dontdiff	Remove gperf usage from toolchain	2017-08-19 11:02:53 -07:00
efi-stub.txt	efi-stub.txt: standardize document format	2017-07-14 13:51:34 -06:00
eisa.txt	eisa.txt: standardize document format	2017-07-14 13:51:34 -06:00
errseq.rst	Documentation: add some docs for errseq_t	2017-07-29 09:01:02 -04:00
flexible-arrays.txt	flexible-arrays.txt: standardize document format	2017-07-14 13:51:35 -06:00
futex-requeue-pi.txt	futex-requeue-pi.txt: standardize document format	2017-07-14 13:51:35 -06:00
gcc-plugins.txt	gcc-plugins.txt: standardize document format	2017-07-14 13:51:36 -06:00
highuid.txt	highuid.txt: standardize document format	2017-07-14 13:51:36 -06:00
hw_random.txt	hw_random.txt: standardize document format	2017-07-14 13:51:37 -06:00
hwspinlock.txt	hwspinlock.txt: standardize document format	2017-07-14 13:51:37 -06:00
index.rst	Make the main documentation title less Geocities	2017-06-23 14:02:27 -06:00
intel_txt.txt	intel_txt.txt: standardize document format	2017-07-14 13:51:38 -06:00
Intel-IOMMU.txt	Intel-IOMMU.txt: standardize document format	2017-07-14 13:51:38 -06:00
io_ordering.txt	io_ordering.txt: standardize document format	2017-07-14 13:51:39 -06:00
io-mapping.txt	io-mapping.txt: standardize document format	2017-07-14 13:51:38 -06:00
iostats.txt	iostats.txt: update it to cover recent Kernels	2017-07-14 13:51:40 -06:00
IPMI.txt	IPMI.txt: standardize document format	2017-07-14 13:51:40 -06:00
IRQ-affinity.txt	IRQ-affinity.txt: standardize document format	2017-07-14 13:51:41 -06:00
IRQ-domain.txt	IRQ-domain.txt: standardize document format	2017-07-14 13:51:41 -06:00
IRQ.txt	IRQ.txt: add a markup for its title	2017-07-14 13:51:42 -06:00
irqflags-tracing.txt	irqflags-tracing.txt: standardize document format	2017-07-14 13:51:42 -06:00
isa.txt	isa.txt: standardize document format	2017-07-14 13:51:43 -06:00
isapnp.txt	isapnp.txt: promote title level	2017-07-14 13:51:43 -06:00
kernel-doc-nano-HOWTO.txt	docs: update old references for DocBook from the documentation	2017-05-16 08:44:19 -03:00
kernel-per-CPU-kthreads.txt	kernel-per-CPU-kthreads.txt: standardize document format	2017-07-14 13:51:43 -06:00
kobject.txt	kobject.txt: standardize document format	2017-07-14 13:51:44 -06:00
kprobes.txt	kprobes/docs: Remove jprobes related documents	2017-10-20 11:02:55 +02:00
kref.txt	kref.txt: standardize document format	2017-07-14 13:51:45 -06:00
ldm.txt	ldm.txt: standardize document format	2017-07-14 13:51:45 -06:00
lockup-watchdogs.txt	lockup-watchdogs.txt: standardize document format	2017-07-14 13:51:46 -06:00
logo.gif
logo.txt
lsm.txt	docs-rst: convert lsm from DocBook to ReST	2017-05-16 08:44:19 -03:00
lzo.txt	lzo.txt: standardize document format	2017-07-14 13:51:46 -06:00
mailbox.txt	mailbox.txt: standardize document format	2017-07-14 13:51:47 -06:00
Makefile	Documentation: add script and build target to check for broken file references	2017-10-12 11:07:42 -06:00
memory-barriers.txt	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-11-13 12:38:26 -08:00
memory-hotplug.txt	memory-hotplug.txt: standardize document format	2017-07-14 13:57:53 -06:00
men-chameleon-bus.txt	men-chameleon-bus.txt: standardize document format	2017-07-14 13:57:54 -06:00
nommu-mmap.txt	nommu-mmap.txt: don't use all upper case on titles	2017-07-14 13:57:55 -06:00
ntb.txt	This series converts a number of top-level documents to the RST format	2017-07-15 12:58:58 -07:00
numastat.txt	numastat.txt: standardize document format	2017-07-14 13:57:56 -06:00
padata.txt	padata.txt: standardize document format	2017-07-14 13:57:56 -06:00
parport-lowlevel.txt	parport-lowlevel.txt: standardize document format	2017-07-14 13:57:57 -06:00
percpu-rw-semaphore.txt	percpu-rw-semaphore.txt: standardize document format	2017-07-14 13:57:58 -06:00
phy.txt	phy.txt: standardize document format	2017-07-14 13:57:58 -06:00
pi-futex.txt	Documentation: fix locking rt-mutex doc refs	2017-10-19 12:56:44 -06:00
pnp.txt	pnp.txt: standardize document format	2017-07-14 13:57:59 -06:00
preempt-locking.txt	preempt-locking.txt: standardize document format	2017-07-14 13:58:00 -06:00
printk-formats.txt	printk-formats.txt: Add examples for %pF and %pS usage	2017-08-24 18:49:52 +02:00
pwm.txt	pwm: Standardize document format	2017-07-06 08:23:30 +02:00
rbtree.txt	rbtree: cache leftmost node internally	2017-09-08 18:26:48 -07:00
remoteproc.txt	remoteproc.txt: standardize document format	2017-07-14 13:58:02 -06:00
rfkill.txt	rfkill.txt: standardize document format	2017-07-14 13:58:02 -06:00
robust-futex-ABI.txt	robust-futex-ABI.txt: standardize document format	2017-07-14 13:58:03 -06:00
robust-futexes.txt	robust-futexes.txt: standardize document format	2017-07-14 13:58:03 -06:00
rpmsg.txt	rpmsg.txt: standardize document format	2017-07-14 13:58:04 -06:00
rtc.txt	rtc: add generic nvmem support	2017-07-07 13:14:14 +02:00
SAK.txt	SAK.txt: standardize document format	2017-07-14 13:58:04 -06:00
sgi-ioc4.txt	sgi-ioc4.txt: standardize document format	2017-07-14 13:58:05 -06:00
siphash.txt	siphash.txt: standardize document format	2017-07-14 13:58:06 -06:00
SM501.txt	SM501.txt: standardize document format	2017-07-14 13:58:06 -06:00
smsc_ece1099.txt	smsc_ece1099.txt: standardize document format	2017-07-14 13:58:07 -06:00
static-keys.txt	jump_label: Provide hotplug context variants	2017-08-10 12:28:59 +02:00
SubmittingPatches
svga.txt	svga.txt: standardize document format	2017-07-14 13:58:08 -06:00
switchtec.txt
sync_file.txt	sync_file.txt: standardize document format	2017-05-24 13:01:27 -03:00
tee.txt	tee.txt: standardize document format	2017-07-14 13:58:14 -06:00
this_cpu_ops.txt	this_cpu_ops.txt: standardize document format	2017-07-14 13:58:08 -06:00
unaligned-memory-access.txt	unaligned-memory-access.txt: standardize document format	2017-07-14 13:58:09 -06:00
vfio-mediated-device.txt	vfio-mediated-device.txt: standardize document format	2017-07-14 13:58:10 -06:00
vfio.txt	vfio.txt: standardize document format	2017-07-14 13:58:10 -06:00
video-output.txt
xillybus.txt	xillybus.txt: standardize document format	2017-07-14 13:58:11 -06:00
xz.txt	xz.txt: standardize document format	2017-07-14 13:58:11 -06:00
zorro.txt	zorro.txt: standardize document format	2017-07-14 13:58:12 -06:00