Aliaksandr Valialkin 76f4fd8a52 runtime: improve timers scalability on multi-CPU systems ... Use per-P timers, so each P may work with its own timers. This CL improves performance on multi-CPU systems in the following cases: - When serving high number of concurrent connections with read/write deadlines set (for instance, highly loaded net/http server). - When using high number of concurrent timers. These timers may be implicitly created via context.WithDeadline or context.WithTimeout. Production servers should usually set timeout on connections and external requests in order to prevent from resource leakage. See https://blog.cloudflare.com/the-complete-guide-to-golang-net-http-timeouts/ Below are relevant benchmark results for various GOMAXPROCS values on linux/amd64: context package: name old time/op new time/op delta WithTimeout/concurrency=40 4.92µs ± 0% 5.17µs ± 1% +5.07% (p=0.000 n=9+9) WithTimeout/concurrency=4000 6.03µs ± 1% 6.49µs ± 0% +7.63% (p=0.000 n=8+10) WithTimeout/concurrency=400000 8.58µs ± 7% 9.02µs ± 4% +5.02% (p=0.019 n=10+10) name old time/op new time/op delta WithTimeout/concurrency=40-2 3.70µs ± 1% 2.78µs ± 4% -24.90% (p=0.000 n=8+9) WithTimeout/concurrency=4000-2 4.49µs ± 4% 3.67µs ± 5% -18.26% (p=0.000 n=10+10) WithTimeout/concurrency=400000-2 6.16µs ±10% 5.15µs ±13% -16.30% (p=0.000 n=10+10) name old time/op new time/op delta WithTimeout/concurrency=40-4 3.58µs ± 1% 2.64µs ± 2% -26.13% (p=0.000 n=9+10) WithTimeout/concurrency=4000-4 4.17µs ± 0% 3.32µs ± 1% -20.36% (p=0.000 n=10+10) WithTimeout/concurrency=400000-4 5.57µs ± 9% 4.83µs ±10% -13.27% (p=0.001 n=10+10) time package: name old time/op new time/op delta AfterFunc 6.15ms ± 3% 6.07ms ± 2% ~ (p=0.133 n=10+9) AfterFunc-2 3.43ms ± 1% 3.56ms ± 1% +3.91% (p=0.000 n=10+9) AfterFunc-4 5.04ms ± 2% 2.36ms ± 0% -53.20% (p=0.000 n=10+9) After 6.54ms ± 2% 6.49ms ± 3% ~ (p=0.393 n=10+10) After-2 3.68ms ± 1% 3.87ms ± 0% +5.14% (p=0.000 n=9+9) After-4 6.66ms ± 1% 2.87ms ± 1% -56.89% (p=0.000 n=10+10) Stop 698µs ± 2% 689µs ± 1% -1.26% (p=0.011 n=10+10) Stop-2 729µs ± 2% 434µs ± 3% -40.49% (p=0.000 n=10+10) Stop-4 837µs ± 3% 333µs ± 2% -60.20% (p=0.000 n=10+10) SimultaneousAfterFunc 694µs ± 1% 692µs ± 7% ~ (p=0.481 n=10+10) SimultaneousAfterFunc-2 714µs ± 3% 569µs ± 2% -20.33% (p=0.000 n=10+10) SimultaneousAfterFunc-4 782µs ± 2% 386µs ± 2% -50.67% (p=0.000 n=10+10) StartStop 267µs ± 3% 274µs ± 0% +2.64% (p=0.000 n=8+9) StartStop-2 238µs ± 2% 140µs ± 3% -40.95% (p=0.000 n=10+8) StartStop-4 320µs ± 1% 125µs ± 1% -61.02% (p=0.000 n=9+9) Reset 75.0µs ± 1% 77.5µs ± 2% +3.38% (p=0.000 n=10+10) Reset-2 150µs ± 2% 40µs ± 5% -73.09% (p=0.000 n=10+9) Reset-4 226µs ± 1% 33µs ± 1% -85.42% (p=0.000 n=10+10) Sleep 857µs ± 6% 878µs ± 9% ~ (p=0.079 n=10+9) Sleep-2 617µs ± 4% 585µs ± 2% -5.21% (p=0.000 n=10+10) Sleep-4 689µs ± 3% 465µs ± 4% -32.53% (p=0.000 n=10+10) Ticker 55.9ms ± 2% 55.9ms ± 2% ~ (p=0.971 n=10+10) Ticker-2 28.7ms ± 2% 28.1ms ± 1% -2.06% (p=0.000 n=10+10) Ticker-4 14.6ms ± 0% 13.6ms ± 1% -6.80% (p=0.000 n=9+10) Fixes #15133 Change-Id: I6f4b09d2db8c5bec93146db6501b44dbfe5c0ac4 Reviewed-on: https://go-review.googlesource.com/34784 Reviewed-by: Austin Clements <austin@google.com>		2017-09-12 16:52:23 +00:00
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benchmark_test.go	runtime: improve timers scalability on multi-CPU systems	2017-09-12 16:52:23 +00:00
context_test.go	all: fix minor misspellings	2017-04-03 23:19:07 +00:00
context.go	context: fix lint warning “drop = 0 from declaration”	2017-08-30 17:06:30 +00:00
example_test.go
net_test.go
x_test.go	context: adjust tests to avoid importing "testing" in package context	2016-11-03 21:12:21 +00:00