linux/tools
Davidlohr Bueso e2e1680fda perf bench futex: Avoid worker cacheline bouncing
Sebastian noted that overhead for worker thread ops (throughput)
accounting was producing 'perf' to appear in the profiles, consuming a
non-trivial (i.e. 13%) amount of CPU.

This is due to cacheline bouncing due to the increment of w->ops.

We can easily fix this by just working on a local copy and updating the
actual worker once done running, and ready to show the program summary.
There is no danger of the worker being concurrent, so we can trust that
no stale value is being seen by another thread.

This also gets rid of the unnecessary cache alignment hack; its not
worth it.

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/1477342613-9938-2-git-send-email-dave@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
History 2016-10-25 09:50:47 -03:00
..
accounting tools: move accounting tool from Documentation 2016-09-23 13:07:15 -06:00
arch tools: Synchronize tools/arch/x86/include/asm/cpufeatures.h 2016-10-05 19:18:34 -03:00
build tools build: Add feature detection for g++ 2016-10-05 19:59:35 -03:00
cgroup cgroups: fix cgroup_event_listener error handling 2013-01-08 10:00:44 -08:00
firewire tools/firewire: nosy-dump: check for allocation failure 2012-12-02 20:10:18 +01:00
gpio tools/gpio: fix gpio-event-mon header comment 2016-08-08 09:50:22 +02:00
hv Drivers: hv: utils: Check VSS daemon is listening before a hot backup 2016-09-02 17:22:51 +02:00
iio Second set of iio new device support, features and cleanups for the 4.9 cycle. 2016-09-14 20:42:03 +02:00
include tools lib: Add for_each_clear_bit macro 2016-10-24 11:07:33 -03:00
kvm/kvm_stat tools: kvm_stat: Add comments 2016-05-25 16:12:06 +02:00
laptop tools: move laptops dslm tool from Documentation 2016-09-23 13:07:21 -06:00
lguest tools/lguest: Don't bork the terminal in case of wrong args 2016-09-08 08:05:24 +02:00
lib tools lib: Add for_each_clear_bit macro 2016-10-24 11:07:33 -03:00
net tools: bpf_jit_disasm: check for klogctl failure 2016-05-08 23:32:59 -04:00
nfsd NFSD: Added fault injection script 2011-11-07 21:10:47 -05:00
objtool objtool: Skip all "unreachable instruction" warnings for gcov kernels 2016-10-16 09:12:36 +02:00
pcmcia tools: move pcmcia crc32hash tool from Documentation 2016-09-23 13:07:27 -06:00
perf perf bench futex: Avoid worker cacheline bouncing 2016-10-25 09:50:47 -03:00
power ACPICA: Cleanup for all string-to-integer conversions 2016-09-10 02:37:59 +02:00
scripts tools build: Fix objtool build with ARCH=x86_64 2016-07-22 16:37:44 -03:00
spi Merge remote-tracking branches 'spi/topic/ti-qspi', 'spi/topic/tools', 'spi/topic/txx9' and 'spi/topic/xlp' into spi-next 2016-09-30 09:14:22 -07:00
testing linux-kselftest-4.9-rc1-update 2016-10-14 15:17:12 -07:00
thermal/tmon tools/thermal: tmon: use pkg-config also for CFLAGS 2015-10-10 11:32:31 +08:00
time tools: add script to test udelay 2014-07-23 10:16:38 -07:00
usb usbip: adding names db to port operation 2016-05-03 14:32:07 -07:00
virtio tools/virtio: add dma stubs 2016-08-15 05:05:51 +03:00
vm tools/vm/page_owner: increase temporary buffer size 2016-07-26 16:19:19 -07:00
Makefile tools/gpio: add install section 2016-06-23 11:07:13 +02:00