Bryan C. Mills e9702c0c85 expvar: reduce sync.Map overhead for (*Map).Set ... 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>		2017-05-02 17:13:40 +00:00
..
expvar_test.go	expvar: replace RWMutex usage with sync.Map and atomics	2017-04-28 21:59:55 +00:00
expvar.go	expvar: reduce sync.Map overhead for (*Map).Set	2017-05-02 17:13:40 +00:00