linux/Documentation
Paolo Valente 43c1b3d6e5 block, bfq: stress that low_latency must be off to get max throughput
The introduction of the BFQ and Kyber I/O schedulers has triggered a
new wave of I/O benchmarks. Unfortunately, comments and discussions on
these benchmarks confirm that there is still little awareness that it
is very hard to achieve, at the same time, a low latency and a high
throughput. In particular, virtually all benchmarks measure
throughput, or throughput-related figures of merit, but, for BFQ, they
use the scheduler in its default configuration. This configuration is
geared, instead, toward a low latency. This is evidently a sign that
BFQ documentation is still too unclear on this important aspect. This
commit addresses this issue by stressing how BFQ configuration must be
(easily) changed if the only goal is maximum throughput.

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-10 07:39:43 -06:00
..
ABI Staging/IIO patches for 4.12-rc1 2017-05-05 18:16:23 -07:00
accounting tools: move accounting tool from Documentation 2016-09-23 13:07:15 -06:00
acpi A reasonably busy cycle for documentation this time around. There is a new 2017-05-02 10:21:17 -07:00
admin-guide Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-05-03 10:05:38 -07:00
aoe
arm arm: Documentation: update a path name 2017-04-20 14:06:55 -06:00
arm64 Pre-requisites for the arch timer errata workarounds: 2017-04-07 17:04:19 +01:00
auxdisplay samples: move auxdisplay example code from Documentation 2016-09-23 11:52:32 -06:00
backlight
blackfin samples: move blackfin gptimers-example from Documentation 2016-10-10 07:12:02 -06:00
block block, bfq: stress that low_latency must be off to get max throughput 2017-05-10 07:39:43 -06:00
blockdev remove the mg_disk driver 2017-04-14 14:00:49 -06:00
bus-devices
cdrom cdrom: Make device operations read-only 2017-02-14 08:29:56 -07:00
cgroup-v1 Merge branch 'for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2017-02-27 21:41:08 -08:00
cma
connector
console
core-api docs-rst: core_api: move driver-specific stuff to drivers_api 2017-04-02 14:17:43 -06:00
cpu-freq cpufreq: User/admin documentation update and consolidation 2017-03-13 17:08:42 -06:00
cpuidle
cris
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-05-03 08:50:52 -07:00
dev-tools scripts/spelling.txt: add "disble(d)" pattern and fix typo instances 2017-03-09 17:01:09 -08:00
device-mapper - A major update for DM cache that reduces the latency for deciding 2017-05-03 10:31:20 -07:00
devicetree DeviceTree for 4.12: 2017-05-05 19:33:07 -07:00
dmaengine dmaengine: Documentation: Fix typo in pxa_dma.txt 2016-11-14 08:14:24 +05:30
doc-guide docs-rst: automatically convert Graphviz and SVG images 2017-03-09 02:59:26 -07:00
DocBook char/misc patches for 4.12-rc1 2017-05-04 19:15:35 -07:00
driver-api char/misc patches for 4.12-rc1 2017-05-04 19:15:35 -07:00
driver-model irqdesc: Add a resource managed version of irq_alloc_descs() 2017-02-10 14:39:20 +01:00
early-userspace Documentation: Fix dead URLs to ftp.kernel.org 2017-03-29 15:46:06 -06:00
EDID drm: use .hword to represent 16-bit numbers 2017-03-30 10:15:19 +02:00
extcon extcon: Remove porting compatibility of swich class 2017-04-06 10:55:24 +09:00
fault-injection
fb
features powerpc updates for 4.12 part 1. 2017-05-05 11:36:44 -07:00
filesystems proc: show MADV_FREE pages info in smaps 2017-05-03 15:52:08 -07:00
firmware_class firmware: revamp firmware documentation 2017-01-11 09:42:59 +01:00
fmc
fpga fpga: Add scatterlist based programming 2017-02-10 15:20:44 +01:00
frv docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
gpio gpio: return NULL from gpiod_get_optional when GPIOLIB is disabled 2017-03-15 11:16:30 +01:00
gpu drm: Document code of conduct 2017-05-05 11:48:17 +10:00
hid Documentation: hid: fix path to input bus definitions 2017-03-13 17:15:19 -06:00
hwmon drivers: hwmon: Support for ASPEED PWM/Fan tach 2017-04-10 13:12:18 -07:00
i2c i2c: i801: Add support for Intel Gemini Lake 2017-02-09 17:39:16 +01:00
ia64 selftests: move ia64 tests from Documentation/ia64 2016-09-20 09:58:12 -06:00
ide
iio iio: Documentation: Correct the path used to create triggers. 2016-10-01 00:49:58 -06:00
infiniband IB/opa-vnic: Virtual Network Interface Controller (VNIC) documentation 2017-04-20 12:01:06 -04:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2017-05-03 12:38:20 -07:00
ioctl docs: Fix a spelling error in ioctl-number.txt 2017-04-27 15:54:38 -06:00
isdn docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
kbuild Kconfig: Introduce the "imply" keyword 2016-11-16 09:26:33 +01:00
kdump Documentation: kdump: describe arm64 port 2017-04-05 18:32:32 +01:00
laptops platform/x86: thinkpad_acpi: Add support for X1 Yoga (2016) Tablet Mode 2016-12-13 09:29:06 -08:00
leds Documentaion: leds: leds-lp55xx.txt: Fix typos 2017-03-17 13:06:14 -06:00
lightnvm lightnvm: physical block device (pblk) target 2017-04-16 10:06:33 -06:00
livepatch livepatch: allow removal of a disabled patch 2017-03-08 09:38:43 +01:00
locking locking/ww_mutex/Documentation: Update the design document 2017-01-14 11:14:55 +01:00
m68k docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
md Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-05-03 10:05:38 -07:00
media media updates for v4.12-rc1 2017-05-05 17:34:57 -07:00
memory-devices
metag
mic samples: move mic/mpssd example code from Documentation 2016-09-20 12:38:48 -06:00
mips
misc-devices samples: move misc-devices/mei example code from Documentation 2016-09-23 11:51:43 -06:00
mmc MMC core: 2017-05-02 17:34:32 -07:00
mn10300
mtd spi-nor: Add support for Intel SPI serial flash controller 2017-01-03 17:33:36 +00:00
namespaces
netlabel
networking Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-05-02 16:40:27 -07:00
nfc
nios2
nvdimm
nvmem
parisc
PCI pci-error-recovery: doc cleanup 2017-03-29 15:51:32 -06:00
pcmcia tools: move pcmcia crc32hash tool from Documentation 2016-09-23 13:07:27 -06:00
perf perf: qcom: Add L3 cache PMU driver 2017-04-03 18:53:50 +01:00
phy
platform
power A reasonably busy cycle for documentation this time around. There is a new 2017-05-02 10:21:17 -07:00
powerpc powerpc updates for 4.12 part 1. 2017-05-05 11:36:44 -07:00
pps Doc: clarify source of jitter in USB1.1, and USB2.0 2017-01-04 14:40:52 -07:00
prctl selftests: move prctl tests from Documentation/prctl 2016-09-20 09:09:09 -06:00
process docs: complete bumping minimal GNU Make version to 3.81 2017-05-06 18:49:09 -07:00
pti
ptp selftests: move ptp tests from Documentation/ptp 2016-09-20 09:54:38 -06:00
rapidio
RCU Merge branches 'doc.2017.01.15b', 'dyntick.2017.01.23a', 'fixes.2017.01.23a', 'srcu.2017.01.25a' and 'torture.2017.01.15b' into HEAD 2017-01-25 12:56:05 -08:00
s390 docs: add documentation for vfio-ccw 2017-03-31 12:55:11 +02:00
scheduler sched/Documentation: Add 'sched-pelt' tool 2017-04-14 10:26:35 +02:00
scsi scsi: make asynchronous aborts mandatory 2017-04-06 13:07:33 -04:00
security KEYS: add SP800-56A KDF support for DH 2017-04-04 22:33:38 +01:00
serial
sh
sound ALSA: hda - Allow to enable/disable vmaster build explicitly 2017-04-10 17:45:27 +02:00
sparc Documentation/sparc: Steps for sending break on sunhv console 2017-02-23 08:27:25 -08:00
sphinx tmplcvt: make the tool more robust 2017-04-11 14:35:15 -06:00
sphinx-static This is the documentation update pull for the 4.9 merge window. 2016-10-04 13:54:07 -07:00
spi spi: spi-ep93xx: simplify GPIO chip selects 2017-02-16 20:10:26 +00:00
sysctl Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning 2017-04-21 13:22:34 -04:00
target
thermal Doc/PM: Sync with intel_powerclamp code behavior 2017-04-20 15:35:03 -06:00
timers time: Remove CONFIG_TIMER_STATS 2017-02-10 11:15:08 +01:00
trace New features for this release: 2017-05-03 18:41:21 -07:00
translations Documentation: Add HOWTO Japanese translation into rst based build system 2017-04-08 11:13:05 -06:00
usb USB patches for 4.12-rc1 2017-05-04 18:03:51 -07:00
userspace-api docs: Convert unshare.txt to RST and add to the user-space API manual 2017-04-02 15:18:32 -06:00
virtual KVM/ARM Fixes for v4.11-rc6 2017-04-05 16:27:47 +02:00
vm Documentation: vm, add hugetlbfs reservation overview 2017-05-03 15:52:11 -07:00
w1 w1: add documentation for w1_ds2438 2017-03-17 15:10:49 +09:00
watchdog watchdog: Introduce watchdog_stop_on_unregister helper 2017-02-24 14:00:23 -08:00
wimax
x86 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-01 23:54:56 -07:00
xtensa
.gitignore
00-INDEX Documentation: move MD related doc into a separate dir 2017-02-13 09:17:53 -08:00
bcache.txt
bt8xxgpio.txt
btmrvl.txt
bus-virt-phys-mapping.txt
cachetlb.txt
cgroup-v2.txt mm: memcontrol: provide shmem statistics 2017-05-03 15:52:08 -07:00
Changes docs: add back 'Documentation/Changes' file (as symlink) 2016-12-14 16:30:12 -08:00
circular-buffers.txt Documentation: circular-buffers: use READ_ONCE() 2016-11-16 16:17:45 -07:00
clk.txt
CodingStyle doc: re-add CodingStyle and SubmittingPatches 2016-10-24 08:12:35 -02:00
conf.py Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2017-05-03 12:38:20 -07:00
cpu-load.txt
cputopology.txt docs: Fix a couple typos 2017-04-27 15:54:39 -06:00
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt docs: Fix a couple typos 2017-04-27 15:54:39 -06:00
dell_rbu.txt
digsig.txt
DMA-API-HOWTO.txt Documentation: DMA-API-HOWTO: Fix a typo 2016-09-20 17:58:46 -06:00
DMA-API.txt dma-mapping: add dma_{map,unmap}_resource 2016-09-26 22:16:41 +05:30
DMA-attributes.txt common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute 2017-01-19 15:56:19 +00:00
DMA-ISA-LPC.txt Documentation: DMA-ISA-LPC.txt 2017-02-12 15:20:07 -07:00
docutils.conf
dontdiff Documentation: dontdiff: Update with additional entries 2017-01-26 15:08:06 -07:00
efi-stub.txt
eisa.txt
flexible-arrays.txt
futex-requeue-pi.txt
gcc-plugins.txt gcc-plugins: update architecture list in documentation 2017-03-21 22:20:05 +11:00
highuid.txt
hw_random.txt
hwspinlock.txt
index.rst Merge branch 'user-space-api' into docs-next 2017-04-08 11:25:37 -06:00
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt Documentation: Fix a typo in IPMI.txt. 2017-01-05 15:01:54 -06:00
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
isa.txt
isapnp.txt
kernel-doc-nano-HOWTO.txt docs-rst: doc-guide: split the kernel-documentation.rst contents 2016-11-19 10:22:04 -07:00
kernel-per-CPU-kthreads.txt docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
kobject.txt
kprobes.txt
kref.txt Revert "kref: double kref_put() in my_data_handler()" 2017-04-08 18:38:10 +02:00
kselftest.txt scripts/spelling.txt: add "an user" pattern and fix typo instances 2017-02-27 18:43:46 -08:00
ldm.txt
lockup-watchdogs.txt docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
logo.gif
logo.txt
lzo.txt
mailbox.txt
Makefile samples: move blackfin gptimers-example from Documentation 2016-10-10 07:12:02 -06:00
Makefile.sphinx Add a target to check broken external links in the Documentation 2017-02-15 15:22:47 -07:00
memory-barriers.txt doc: Update control-dependencies section of memory-barriers.txt 2017-01-14 21:29:15 -08:00
memory-hotplug.txt scripts/spelling.txt: add "followings" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
men-chameleon-bus.txt
nommu-mmap.txt
ntb.txt
numastat.txt
padata.txt
parport-lowlevel.txt
percpu-rw-semaphore.txt
phy.txt Documentation: phy: Fix repetition of word 'the' 2017-03-09 00:33:15 -07:00
pi-futex.txt
pinctrl.txt pinctrl: core: Fix pinctrl_register_and_init() with pinctrl_enable() 2017-04-07 01:08:08 +02:00
pnp.txt
preempt-locking.txt
printk-formats.txt
pwm.txt
rbtree.txt
remoteproc.txt remoteproc: Split driver and consumer dereferencing 2016-10-02 22:50:21 -07:00
rfkill.txt docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rtc.txt
SAK.txt
sgi-ioc4.txt
siphash.txt siphash: implement HalfSipHash1-3 for hash tables 2017-01-09 13:58:57 -05:00
SM501.txt
smsc_ece1099.txt
static-keys.txt docs: Fix a couple typos 2017-04-27 15:54:39 -06:00
SubmittingPatches doc: re-add CodingStyle and SubmittingPatches 2016-10-24 08:12:35 -02:00
svga.txt
sync_file.txt Documentation: sync_file.txt: Fix typos 2017-03-17 13:03:36 -06:00
this_cpu_ops.txt
unaligned-memory-access.txt Documentation/unaligned-memory-access.txt: fix incorrect comparison operator 2016-12-27 13:08:42 -07:00
vfio-mediated-device.txt docs: Fix a spelling error in vfio-mediated-device.txt 2017-04-27 15:54:39 -06:00
vfio.txt
video-output.txt
xillybus.txt
xz.txt
zorro.txt docs: Fix a couple typos 2017-04-27 15:54:39 -06:00