Dmitriy Vyukov
4e5086b993
runtime: improve Linux mutex
...
The implementation is hybrid active/passive spin/blocking mutex.
The design minimizes amount of context switches and futex calls.
The idea is that all critical sections in runtime are intentially
small, so pure blocking mutex behaves badly causing
a lot of context switches, thread parking/unparking and kernel calls.
Note that some synthetic benchmarks become somewhat slower,
that's due to increased contention on other data structures,
it should not affect programs that do any real work.
On 2 x Intel E5620, 8 HT cores, 2.4GHz
benchmark old ns/op new ns/op delta
BenchmarkSelectContended 521.00 503.00 -3.45%
BenchmarkSelectContended-2 661.00 320.00 -51.59%
BenchmarkSelectContended-4 1139.00 629.00 -44.78%
BenchmarkSelectContended-8 2870.00 878.00 -69.41%
BenchmarkSelectContended-16 5276.00 818.00 -84.50%
BenchmarkChanContended 112.00 103.00 -8.04%
BenchmarkChanContended-2 631.00 174.00 -72.42%
BenchmarkChanContended-4 682.00 272.00 -60.12%
BenchmarkChanContended-8 1601.00 520.00 -67.52%
BenchmarkChanContended-16 3100.00 372.00 -88.00%
BenchmarkChanSync 253.00 239.00 -5.53%
BenchmarkChanSync-2 5030.00 4648.00 -7.59%
BenchmarkChanSync-4 4826.00 4694.00 -2.74%
BenchmarkChanSync-8 4778.00 4713.00 -1.36%
BenchmarkChanSync-16 5289.00 4710.00 -10.95%
BenchmarkChanProdCons0 273.00 254.00 -6.96%
BenchmarkChanProdCons0-2 599.00 400.00 -33.22%
BenchmarkChanProdCons0-4 1168.00 659.00 -43.58%
BenchmarkChanProdCons0-8 2831.00 1057.00 -62.66%
BenchmarkChanProdCons0-16 4197.00 1037.00 -75.29%
BenchmarkChanProdCons10 150.00 140.00 -6.67%
BenchmarkChanProdCons10-2 607.00 268.00 -55.85%
BenchmarkChanProdCons10-4 1137.00 404.00 -64.47%
BenchmarkChanProdCons10-8 2115.00 828.00 -60.85%
BenchmarkChanProdCons10-16 4283.00 855.00 -80.04%
BenchmarkChanProdCons100 117.00 110.00 -5.98%
BenchmarkChanProdCons100-2 558.00 218.00 -60.93%
BenchmarkChanProdCons100-4 722.00 287.00 -60.25%
BenchmarkChanProdCons100-8 1840.00 431.00 -76.58%
BenchmarkChanProdCons100-16 3394.00 448.00 -86.80%
BenchmarkChanProdConsWork0 2014.00 1996.00 -0.89%
BenchmarkChanProdConsWork0-2 1207.00 1127.00 -6.63%
BenchmarkChanProdConsWork0-4 1913.00 611.00 -68.06%
BenchmarkChanProdConsWork0-8 3016.00 949.00 -68.53%
BenchmarkChanProdConsWork0-16 4320.00 1154.00 -73.29%
BenchmarkChanProdConsWork10 1906.00 1897.00 -0.47%
BenchmarkChanProdConsWork10-2 1123.00 1033.00 -8.01%
BenchmarkChanProdConsWork10-4 1076.00 571.00 -46.93%
BenchmarkChanProdConsWork10-8 2748.00 1096.00 -60.12%
BenchmarkChanProdConsWork10-16 4600.00 1105.00 -75.98%
BenchmarkChanProdConsWork100 1884.00 1852.00 -1.70%
BenchmarkChanProdConsWork100-2 1235.00 1146.00 -7.21%
BenchmarkChanProdConsWork100-4 1217.00 619.00 -49.14%
BenchmarkChanProdConsWork100-8 1534.00 509.00 -66.82%
BenchmarkChanProdConsWork100-16 4126.00 918.00 -77.75%
BenchmarkSyscall 34.40 33.30 -3.20%
BenchmarkSyscall-2 160.00 121.00 -24.38%
BenchmarkSyscall-4 131.00 136.00 +3.82%
BenchmarkSyscall-8 139.00 131.00 -5.76%
BenchmarkSyscall-16 161.00 168.00 +4.35%
BenchmarkSyscallWork 950.00 950.00 +0.00%
BenchmarkSyscallWork-2 481.00 480.00 -0.21%
BenchmarkSyscallWork-4 268.00 270.00 +0.75%
BenchmarkSyscallWork-8 156.00 169.00 +8.33%
BenchmarkSyscallWork-16 188.00 184.00 -2.13%
BenchmarkSemaSyntNonblock 36.40 35.60 -2.20%
BenchmarkSemaSyntNonblock-2 81.40 45.10 -44.59%
BenchmarkSemaSyntNonblock-4 126.00 108.00 -14.29%
BenchmarkSemaSyntNonblock-8 112.00 112.00 +0.00%
BenchmarkSemaSyntNonblock-16 110.00 112.00 +1.82%
BenchmarkSemaSyntBlock 35.30 35.30 +0.00%
BenchmarkSemaSyntBlock-2 118.00 124.00 +5.08%
BenchmarkSemaSyntBlock-4 105.00 108.00 +2.86%
BenchmarkSemaSyntBlock-8 101.00 111.00 +9.90%
BenchmarkSemaSyntBlock-16 112.00 118.00 +5.36%
BenchmarkSemaWorkNonblock 810.00 811.00 +0.12%
BenchmarkSemaWorkNonblock-2 476.00 414.00 -13.03%
BenchmarkSemaWorkNonblock-4 238.00 228.00 -4.20%
BenchmarkSemaWorkNonblock-8 140.00 126.00 -10.00%
BenchmarkSemaWorkNonblock-16 117.00 116.00 -0.85%
BenchmarkSemaWorkBlock 810.00 811.00 +0.12%
BenchmarkSemaWorkBlock-2 454.00 466.00 +2.64%
BenchmarkSemaWorkBlock-4 243.00 241.00 -0.82%
BenchmarkSemaWorkBlock-8 145.00 137.00 -5.52%
BenchmarkSemaWorkBlock-16 132.00 123.00 -6.82%
BenchmarkContendedSemaphore 123.00 102.00 -17.07%
BenchmarkContendedSemaphore-2 34.80 34.90 +0.29%
BenchmarkContendedSemaphore-4 34.70 34.80 +0.29%
BenchmarkContendedSemaphore-8 34.70 34.70 +0.00%
BenchmarkContendedSemaphore-16 34.80 34.70 -0.29%
BenchmarkMutex 26.80 26.00 -2.99%
BenchmarkMutex-2 108.00 45.20 -58.15%
BenchmarkMutex-4 103.00 127.00 +23.30%
BenchmarkMutex-8 109.00 147.00 +34.86%
BenchmarkMutex-16 102.00 152.00 +49.02%
BenchmarkMutexSlack 27.00 26.90 -0.37%
BenchmarkMutexSlack-2 149.00 165.00 +10.74%
BenchmarkMutexSlack-4 121.00 209.00 +72.73%
BenchmarkMutexSlack-8 101.00 158.00 +56.44%
BenchmarkMutexSlack-16 97.00 129.00 +32.99%
BenchmarkMutexWork 792.00 794.00 +0.25%
BenchmarkMutexWork-2 407.00 409.00 +0.49%
BenchmarkMutexWork-4 220.00 209.00 -5.00%
BenchmarkMutexWork-8 267.00 160.00 -40.07%
BenchmarkMutexWork-16 315.00 300.00 -4.76%
BenchmarkMutexWorkSlack 792.00 793.00 +0.13%
BenchmarkMutexWorkSlack-2 406.00 404.00 -0.49%
BenchmarkMutexWorkSlack-4 225.00 212.00 -5.78%
BenchmarkMutexWorkSlack-8 268.00 136.00 -49.25%
BenchmarkMutexWorkSlack-16 300.00 300.00 +0.00%
BenchmarkRWMutexWrite100 27.10 27.00 -0.37%
BenchmarkRWMutexWrite100-2 33.10 40.80 +23.26%
BenchmarkRWMutexWrite100-4 113.00 88.10 -22.04%
BenchmarkRWMutexWrite100-8 119.00 95.30 -19.92%
BenchmarkRWMutexWrite100-16 148.00 109.00 -26.35%
BenchmarkRWMutexWrite10 29.60 29.40 -0.68%
BenchmarkRWMutexWrite10-2 111.00 61.40 -44.68%
BenchmarkRWMutexWrite10-4 270.00 208.00 -22.96%
BenchmarkRWMutexWrite10-8 204.00 185.00 -9.31%
BenchmarkRWMutexWrite10-16 261.00 190.00 -27.20%
BenchmarkRWMutexWorkWrite100 1040.00 1036.00 -0.38%
BenchmarkRWMutexWorkWrite100-2 593.00 580.00 -2.19%
BenchmarkRWMutexWorkWrite100-4 470.00 365.00 -22.34%
BenchmarkRWMutexWorkWrite100-8 468.00 289.00 -38.25%
BenchmarkRWMutexWorkWrite100-16 604.00 374.00 -38.08%
BenchmarkRWMutexWorkWrite10 951.00 951.00 +0.00%
BenchmarkRWMutexWorkWrite10-2 1001.00 928.00 -7.29%
BenchmarkRWMutexWorkWrite10-4 1555.00 1006.00 -35.31%
BenchmarkRWMutexWorkWrite10-8 2085.00 1171.00 -43.84%
BenchmarkRWMutexWorkWrite10-16 2082.00 1614.00 -22.48%
R=rsc, iant, msolo, fw, iant
CC=golang-dev
https://golang.org/cl/4711045
2011-07-29 12:44:06 -04:00
Russ Cox
8dee872963
runtime: os-specific types and code for setitimer
...
R=r
CC=golang-dev
https://golang.org/cl/4273097
2011-03-23 11:31:42 -04:00
Russ Cox
649aab835f
runtime: add mmap of null page just in case
...
R=r, iant, robert.swiecki, rsc1
CC=golang-dev
https://golang.org/cl/1904044
2010-09-28 20:30:01 -04:00
Russ Cox
5963dbac08
runtime: turn divide by zero, nil dereference into panics
...
tested on linux/amd64, linux/386, linux/arm, darwin/amd64, darwin/386.
freebsd untested; will finish in a separate CL.
for now all the panics are errorStrings.
richer structures can be added as necessary
once the mechanism is shaked out.
R=r
CC=golang-dev
https://golang.org/cl/906041
2010-04-08 18:15:30 -07:00
William Josephson
4c0f262a2d
Remove unnecessary execute bits.
...
R=rsc
https://golang.org/cl/156077
2009-11-18 09:19:29 -08:00
Ian Lance Taylor
f529224039
Get the right sigaction struct for the 386 rt_sigaction system
...
call. This uses the header files from a 32-bit Ubuntu Hardy
system.
The use of _LOOSE_KERNEL_NAMES seems right. The
-D__ARCH_SI_UID_T works around a bug which appears to be fixed
in later Linux versions.
R=rsc
http://go/go-review/1013015
2009-10-26 22:49:08 -07:00
Rob Pike
d90e7cbac6
mv src/lib to src/pkg
...
tests: all.bash passes, gobuild still works, godoc still works.
R=rsc
OCL=30096
CL=30102
2009-06-09 09:53:44 -07:00
