Files · e9702c0c85ea1d1f0de523594d645d255e7351b1 · go / golang

expvar: reduce sync.Map overhead for (*Map).Set · e9702c0c

Bryan C. Mills authored Apr 30, 2017

Use Load instead of LoadOrStore in the fast path to save 1 alloc/op
for existing keys.

name old time/op new time/op delta
IntAdd 6.39ns ± 7% 6.97ns ±19% ~ (p=0.105 n=8+8)
IntAdd-6 12.3ns ± 1% 12.2ns ± 1% ~ (p=0.396 n=7+7)
IntSet 6.41ns ± 6% 6.94ns ±21% ~ (p=0.168 n=8+8)
IntSet-6 12.1ns ± 3% 11.7ns ± 9% ~ (p=0.496 n=7+8)
FloatAdd 14.3ns ± 9% 14.7ns ± 4% ~ (p=0.088 n=8+8)
FloatAdd-6 36.5ns ± 1% 36.6ns ± 0% ~ (p=0.709 n=7+6)
FloatSet 6.59ns ± 7% 6.47ns ± 7% ~ (p=0.397 n=8+7)
FloatSet-6 12.2ns ± 1% 12.2ns ± 2% ~ (p=0.748 n=7+7)
StringSet 67.8ns ± 6% 68.7ns ± 6% ~ (p=0.342 n=8+8)
StringSet-6 41.8ns ± 5% 41.7ns ± 5% ~ (p=0.979 n=8+8)
MapSet 294ns ± 6% 234ns ± 4% -20.35% (p=0.000 n=8+8)
MapSet-6 95.8ns ± 2% 89.4ns ± 3% -6.73% (p=0.000 n=8+8)
MapSetDifferent 1.31µs ± 5% 1.07µs ± 4% -18.21% (p=0.000 n=8+8)
MapSetDifferent-6 260ns ± 8% 210ns ± 9% -19.44% (p=0.000 n=8+8)
MapSetString 294ns ± 6% 236ns ± 4% -19.92% (p=0.000 n=8+8)
MapSetString-6 95.6ns ± 2% 89.9ns ± 2% -5.97% (p=0.000 n=7+8)
MapAddSame 1.46µs ± 3% 1.46µs ± 5% ~ (p=0.721 n=8+8)
MapAddSame-6 328ns ± 6% 330ns ± 4% ~ (p=0.776 n=8+8)
MapAddDifferent 4.89µs ± 7% 4.98µs ± 6% ~ (p=0.505 n=8+8)
MapAddDifferent-6 1.02µs ± 3% 1.01µs ± 4% ~ (p=0.352 n=7+8)
MapAddSameSteadyState 62.1ns ± 7% 60.8ns ± 4% ~ (p=0.521 n=8+8)
MapAddSameSteadyState-6 38.1ns ± 3% 37.7ns ± 0% ~ (p=0.185 n=7+6)
MapAddDifferentSteadyState 290ns ± 5% 293ns ± 4% ~ (p=0.515 n=8+8)
MapAddDifferentSteadyState-6 63.0ns ± 7% 63.7ns ±11% ~ (p=0.482 n=7+8)
RealworldExpvarUsage 7.39µs ± 5% 7.51µs ± 5% ~ (p=0.382 n=8+8)
RealworldExpvarUsage-6 3.07µs ±28% 3.04µs ±43% ~ (p=0.798 n=8+8)

name old alloc/op new alloc/op delta
IntAdd 0.00B 0.00B ~ (all equal)
IntAdd-6 0.00B 0.00B ~ (all equal)
IntSet 0.00B 0.00B ~ (all equal)
IntSet-6 0.00B 0.00B ~ (all equal)
FloatAdd 0.00B 0.00B ~ (all equal)
FloatAdd-6 0.00B 0.00B ~ (all equal)
FloatSet 0.00B 0.00B ~ (all equal)
FloatSet-6 0.00B 0.00B ~ (all equal)
StringSet 16.0B ± 0% 16.0B ± 0% ~ (all equal)
StringSet-6 16.0B ± 0% 16.0B ± 0% ~ (all equal)
MapSet 48.0B ± 0% 32.0B ± 0% -33.33% (p=0.000 n=8+8)
MapSet-6 48.0B ± 0% 32.0B ± 0% -33.33% (p=0.000 n=8+8)
MapSetDifferent 192B ± 0% 128B ± 0% -33.33% (p=0.000 n=8+8)
MapSetDifferent-6 192B ± 0% 128B ± 0% -33.33% (p=0.000 n=8+8)
MapSetString 48.0B ± 0% 32.0B ± 0% -33.33% (p=0.000 n=8+8)
MapSetString-6 48.0B ± 0% 32.0B ± 0% -33.33% (p=0.000 n=8+8)
MapAddSame 480B ± 0% 480B ± 0% ~ (all equal)
MapAddSame-6 480B ± 0% 480B ± 0% ~ (all equal)
MapAddDifferent 1.09kB ± 0% 1.09kB ± 0% ~ (all equal)
MapAddDifferent-6 1.09kB ± 0% 1.09kB ± 0% ~ (all equal)
MapAddSameSteadyState 0.00B 0.00B ~ (all equal)
MapAddSameSteadyState-6 0.00B 0.00B ~ (all equal)
MapAddDifferentSteadyState 0.00B 0.00B ~ (all equal)
MapAddDifferentSteadyState-6 0.00B 0.00B ~ (all equal)
RealworldExpvarUsage 0.00B 0.00B ~ (all equal)
RealworldExpvarUsage-6 0.00B 0.00B ~ (all equal)

name old allocs/op new allocs/op delta
IntAdd 0.00 0.00 ~ (all equal)
IntAdd-6 0.00 0.00 ~ (all equal)
IntSet 0.00 0.00 ~ (all equal)
IntSet-6 0.00 0.00 ~ (all equal)
FloatAdd 0.00 0.00 ~ (all equal)
FloatAdd-6 0.00 0.00 ~ (all equal)
FloatSet 0.00 0.00 ~ (all equal)
FloatSet-6 0.00 0.00 ~ (all equal)
StringSet 1.00 ± 0% 1.00 ± 0% ~ (all equal)
StringSet-6 1.00 ± 0% 1.00 ± 0% ~ (all equal)
MapSet 3.00 ± 0% 2.00 ± 0% -33.33% (p=0.000 n=8+8)
MapSet-6 3.00 ± 0% 2.00 ± 0% -33.33% (p=0.000 n=8+8)
MapSetDifferent 12.0 ± 0% 8.0 ± 0% -33.33% (p=0.000 n=8+8)
MapSetDifferent-6 12.0 ± 0% 8.0 ± 0% -33.33% (p=0.000 n=8+8)
MapSetString 3.00 ± 0% 2.00 ± 0% -33.33% (p=0.000 n=8+8)
MapSetString-6 3.00 ± 0% 2.00 ± 0% -33.33% (p=0.000 n=8+8)
MapAddSame 11.0 ± 0% 11.0 ± 0% ~ (all equal)
MapAddSame-6 11.0 ± 0% 11.0 ± 0% ~ (all equal)
MapAddDifferent 31.0 ± 0% 31.0 ± 0% ~ (all equal)
MapAddDifferent-6 31.0 ± 0% 31.0 ± 0% ~ (all equal)
MapAddSameSteadyState 0.00 0.00 ~ (all equal)
MapAddSameSteadyState-6 0.00 0.00 ~ (all equal)
MapAddDifferentSteadyState 0.00 0.00 ~ (all equal)
MapAddDifferentSteadyState-6 0.00 0.00 ~ (all equal)
RealworldExpvarUsage 0.00 0.00 ~ (all equal)
RealworldExpvarUsage-6 0.00 0.00 ~ (all equal)

https://perf.golang.org/search?q=upload:20170501.1

Change-Id: I28fc3906473f2b7307f6d1ae05a8d9b01ef8a6f8
Reviewed-on: https://go-review.googlesource.com/42211
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

e9702c0c

Name	Last commit	Last update
.github		Loading commit data...
api		Loading commit data...
doc		Loading commit data...
lib/time		Loading commit data...
misc		Loading commit data...
src		Loading commit data...
test		Loading commit data...
.gitattributes		Loading commit data...
.gitignore		Loading commit data...
AUTHORS		Loading commit data...
CONTRIBUTING.md		Loading commit data...
CONTRIBUTORS		Loading commit data...
LICENSE		Loading commit data...
PATENTS		Loading commit data...
README.md		Loading commit data...
favicon.ico		Loading commit data...
robots.txt		Loading commit data...

README.md