Thomas Hellstrom 08295b3b5b locking: Implement an algorithm choice for Wound-Wait mutexes ... The current Wound-Wait mutex algorithm is actually not Wound-Wait but Wait-Die. Implement also Wound-Wait as a per-ww-class choice. Wound-Wait is, contrary to Wait-Die a preemptive algorithm and is known to generate fewer backoffs. Testing reveals that this is true if the number of simultaneous contending transactions is small. As the number of simultaneous contending threads increases, Wait-Wound becomes inferior to Wait-Die in terms of elapsed time. Possibly due to the larger number of held locks of sleeping transactions. Update documentation and callers. Timings using git://people.freedesktop.org/~thomash/ww_mutex_test tag patch-18-06-15 Each thread runs 100000 batches of lock / unlock 800 ww mutexes randomly chosen out of 100000. Four core Intel x86_64: Algorithm #threads Rollbacks time Wound-Wait 4 ~100 ~17s. Wait-Die 4 ~150000 ~19s. Wound-Wait 16 ~360000 ~109s. Wait-Die 16 ~450000 ~82s. Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Gustavo Padovan <gustavo@padovan.org> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Sean Paul <seanpaul@chromium.org> Cc: David Airlie <airlied@linux.ie> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-doc@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Co-authored-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@kernel.org>		2018-07-03 09:44:36 +02:00
..
ABI	ABI: sysfs-devices-system-cpu: remove a broken reference	2018-06-15 18:10:01 -03:00
accelerators	ocxl: Document new OCXL IOCTLs	2018-06-03 20:40:33 +10:00
accounting
acpi	ACPI / Documentation: update ACPI customize method feature docs	2018-06-06 08:48:00 +02:00
admin-guide	kernel-parameters.txt: fix pointers to sound parameters	2018-06-15 18:10:01 -03:00
aoe
arm	ARM: Device-tree updates	2018-06-11 17:57:38 -07:00
arm64	ARM:	2018-04-09 11:42:31 -07:00
auxdisplay	Doc: misc-devices: move lcd-panel-cgram.txt to auxdisplay/	2018-04-12 16:08:02 +02:00
backlight
block	block: remov blk_queue_invalidate_tags	2018-06-15 08:13:35 -06:00
blockdev	zram: introduce zram memory tracking	2018-06-07 17:34:34 -07:00
bpf	bpf, doc: howto use/run the BPF selftests	2018-05-14 23:02:58 -07:00
bus-devices
cdrom	Documentation/cdrom: fix German sharp s in LaTex	2018-03-08 19:35:29 -07:00
cgroup-v1	page cache: use xa_lock	2018-04-11 10:28:39 -07:00
cma
connector
console
core-api	Printk changes for 4.18	2018-06-06 16:04:55 -07:00
cpu-freq	cpufreq: Drop cpufreq_table_validate_and_show()	2018-04-10 08:40:45 +02:00
cpuidle	cpuidle: Add definition of residency to sysfs documentation	2018-04-09 13:44:37 +02:00
crypto	docs: crypto_engine.rst: Fix two parse warnings	2018-06-15 12:48:59 -03:00
dev-tools	doc: dev-tools: kselftest.rst: update contributing new tests	2018-04-27 16:56:15 -06:00
device-mapper	dm: add writecache target	2018-06-08 11:59:51 -04:00
devicetree	drm-misc-next for 4.19:	2018-06-28 13:29:07 +10:00
doc-guide	MAINTAINERS & files: Canonize the e-mails I use at files	2018-05-04 06:21:06 -04:00
driver-api	docs: Fix some broken references	2018-06-15 18:10:01 -03:00
driver-model	serdev: Introduce devm_serdev_device_open()	2018-01-08 10:08:34 +00:00
early-userspace
EDID
extcon
fault-injection	Documentation: nvme: Documentation for nvme fault injection	2018-03-26 08:53:43 -06:00
fb
features	Kbuild: rename HAVE_CC_STACKPROTECTOR config variable	2018-06-15 07:15:28 +09:00
filesystems	The main piece is a set of libceph changes that revamps how OSD	2018-06-15 07:24:58 +09:00
firmware_class
fmc
gpio	Documentation: gpio: Move drivers-on-gpio.txt to driver-api	2018-03-23 04:22:29 +01:00
gpu	Merge branch 'drm-next-4.19' of git://people.freedesktop.org/~agd5f/linux into drm-next	2018-06-22 13:19:05 +10:00
hid
hwmon	docs: Fix more broken references	2018-06-15 18:11:26 -03:00
i2c	Merge branch 'i2c/for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux	2018-06-14 16:21:46 +09:00
ia64	ia64: doc: tweak whitespace for 'console=' parameter	2018-03-05 14:41:38 -08:00
ide
iio
infiniband	Documentation/ABI: update infiniband sysfs interfaces	2018-02-23 08:18:33 -07:00
input	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2018-04-05 13:21:57 -07:00
ioctl	SCSI misc on 20180610	2018-06-10 13:01:12 -07:00
isdn	Documentation/isdn: check and fix dead links ...	2018-03-26 12:31:13 -04:00
kbuild	Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables	2018-06-14 12:21:18 +09:00
kdump
kernel-hacking	Documentation: Fix misconversion of #if	2018-01-17 16:45:01 -07:00
laptops	platform/x86: thinkpad_acpi: silence HKEY 0x6032, 0x60f0, 0x6030	2018-05-07 15:10:31 +03:00
leds
lightnvm
livepatch	livepatch: Remove not longer valid limitations from the documentation	2018-05-24 15:37:57 +02:00
locking	locking: Implement an algorithm choice for Wound-Wait mutexes	2018-07-03 09:44:36 +02:00
m68k
maintainer	docs: Fix more broken references	2018-06-15 18:11:26 -03:00
md	raid5-ppl: PPL support for disks with write-back cache enabled	2018-01-15 14:29:42 -08:00
media	media: cec: improve cec status documentation	2018-05-25 15:34:50 -04:00
memory-devices
mic
mips	Documentation: mips: Update AU1xxx_IDE Kconfig dependencies	2018-02-01 12:45:35 -07:00
misc-devices	Mostly small fixes and cleanups, plus a non-trivial fix for charlcd	2018-06-07 14:01:16 -07:00
mmc
mtd
namespaces
netlabel
networking	docs: can.rst: fix a footnote reference	2018-06-15 12:48:59 -03:00
nfc
nios2
nvdimm
nvmem
openrisc
parisc
PCI	PCI/AER: Handle ERR_FATAL with removal and re-enumeration of devices	2018-05-17 16:44:13 -05:00
pcmcia
perf	drivers/bus: Move Arm CCN PMU driver	2018-03-06 17:26:15 +01:00
phy
platform
power	firmware: Fix firmware documentation for recent file renames	2018-04-23 13:03:26 +02:00
powerpc
pps
process	There's been a fair amount of work in the docs tree this time around,	2018-06-04 12:34:27 -07:00
pti
ptp	ptp: Fix documentation to match code.	2018-03-26 12:13:21 -04:00
rapidio	Documentation: rapidio: move sysfs interface to ABI	2018-02-23 08:25:45 -07:00
RCU	doc: Ensure whatisRCU.txt actually says what RCU is	2018-05-15 10:28:12 -07:00
riscv	perf: riscv: Add Document for Future Porting Guide	2018-06-04 14:02:11 -07:00
s390	vfio-ccw: update documentation	2018-03-01 17:32:14 +01:00
scheduler	sched/deadline/Documentation: Add overrun signal and GRUB-PA documentation	2018-05-14 09:12:27 +02:00
scsi	block: remove BLK_EH_HANDLED	2018-05-29 08:59:21 -06:00
security	Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables	2018-06-14 12:21:18 +09:00
serial
sh
sound	sound updates for 4.18	2018-06-06 09:08:38 -07:00
sparc	sparc64: Add support for ADI (Application Data Integrity)	2018-03-18 07:38:48 -07:00
sphinx	Documentation: rstFlatTable.py: fix a broken reference	2018-06-15 18:10:01 -03:00
sphinx-static
spi
sysctl	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2018-06-06 18:39:49 -07:00
target
thermal	thermal: Add cooling device's statistics in sysfs	2018-04-02 21:49:01 +08:00
timers	sched/isolation: Eliminate NO_HZ_FULL_ALL	2018-02-15 15:40:37 -08:00
trace	docs: Fix some broken references	2018-06-15 18:10:01 -03:00
translations	fix a series of Documentation/ broken file name references	2018-06-15 18:10:01 -03:00
usb	Documentation updates for 4.16. New stuff includes refcount_t	2018-01-31 19:25:25 -08:00
userspace-api	audit/stable-4.18 PR 20180605	2018-06-06 16:34:00 -07:00
virtual	KVM: docs: nVMX: Remove known limitations as they do not exist now	2018-06-01 19:18:28 +02:00
vm	docs/vm: move ksm and transhuge from "user" to "internals" section.	2018-05-29 06:45:55 -06:00
w1	Documentation updates for 4.16. New stuff includes refcount_t	2018-01-31 19:25:25 -08:00
watchdog	watchdog: remove bfin_wdt driver	2018-03-26 15:57:04 +02:00
wimax
x86	Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-06-04 21:34:39 -07:00
xtensa
.gitignore
00-INDEX	docs: admin-guide: add cgroup-v2 documentation	2018-05-10 15:42:41 -06:00
atomic_bitops.txt	locking/atomic/bitops: Document and clarify ordering semantics for failed test_and_{}_bit()	2018-02-13 14:55:53 +01:00
atomic_t.txt
bt8xxgpio.txt
btmrvl.txt
bus-virt-phys-mapping.txt
Changes
clearing-warn-once.txt
CodingStyle
conf.py
cpu-load.txt
cputopology.txt
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt	Documentation: remove stale firmware API reference	2018-05-14 16:44:41 +02:00
digsig.txt
DMA-API-HOWTO.txt
DMA-API.txt
DMA-attributes.txt
DMA-ISA-LPC.txt
docutils.conf
dontdiff
efi-stub.txt
eisa.txt
flexible-arrays.txt
futex-requeue-pi.txt
gcc-plugins.txt
highuid.txt
hw_random.txt
hwspinlock.txt
index.rst	docs/vm: add index.rst and link MM documentation to top level index	2018-04-16 14:18:15 -06:00
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt	irqdomain: Kill CONFIG_IRQ_DOMAIN_DEBUG	2018-01-24 12:32:58 +01:00
IRQ.txt
irqflags-tracing.txt
isa.txt
isapnp.txt
kernel-per-CPU-kthreads.txt
kobject.txt
kprobes.txt	docs: Fix some broken references	2018-06-15 18:10:01 -03:00
kref.txt
ldm.txt
lockup-watchdogs.txt
logo.gif
logo.txt
lsm.txt
lzo.txt
mailbox.txt
Makefile
memory-barriers.txt	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-06-04 16:40:11 -07:00
memory-hotplug.txt
men-chameleon-bus.txt
nommu-mmap.txt
ntb.txt
numastat.txt
padata.txt
parport-lowlevel.txt
percpu-rw-semaphore.txt
phy.txt
pi-futex.txt
pnp.txt
preempt-locking.txt
pwm.txt
rbtree.txt
remoteproc.txt
rfkill.txt
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rtc.txt	Documentation: rtc: move iotcl interface documentation to ABI	2018-01-12 00:20:41 +01:00
SAK.txt
sgi-ioc4.txt
siphash.txt
SM501.txt
smsc_ece1099.txt
speculation.txt	Documentation: Document array_index_nospec	2018-01-30 21:54:28 +01:00
static-keys.txt
SubmittingPatches
svga.txt
switchtec.txt
sync_file.txt
tee.txt
this_cpu_ops.txt
unaligned-memory-access.txt
vfio-mediated-device.txt	vfio/mdev: Check globally for duplicate devices	2018-06-08 10:24:27 -06:00
vfio.txt	vfio: fix documentation	2018-05-08 09:16:41 -06:00
video-output.txt
xillybus.txt
xz.txt
zorro.txt