runtime: perform mark 2 root re-scanning in GC workers
This moves another root scanning task out of the GC coordinator and
parallelizes it on the GC workers.
This has negligible effect on the go1 benchmarks and the garbage
benchmark.
name old time/op new time/op delta
XBenchGarbage-12 5.24ms ± 1% 5.26ms ± 1% +0.30% (p=0.007 n=18+17)
name old time/op new time/op delta
BinaryTree17-12 3.20s ± 5% 3.21s ± 5% ~ (p=0.264 n=20+18)
Fannkuch11-12 2.46s ± 1% 2.54s ± 2% +3.09% (p=0.000 n=18+20)
FmtFprintfEmpty-12 49.9ns ± 4% 50.0ns ± 5% ~ (p=0.356 n=20+20)
FmtFprintfString-12 170ns ± 1% 170ns ± 2% ~ (p=0.815 n=19+20)
FmtFprintfInt-12 160ns ± 1% 159ns ± 1% -0.63% (p=0.003 n=18+19)
FmtFprintfIntInt-12 270ns ± 1% 267ns ± 1% -1.00% (p=0.000 n=19+18)
FmtFprintfPrefixedInt-12 238ns ± 1% 232ns ± 1% -2.28% (p=0.000 n=19+19)
FmtFprintfFloat-12 310ns ± 2% 313ns ± 2% +0.93% (p=0.000 n=19+19)
FmtManyArgs-12 1.06µs ± 1% 1.04µs ± 1% -1.93% (p=0.000 n=20+19)
GobDecode-12 8.63ms ± 1% 8.70ms ± 1% +0.81% (p=0.001 n=20+19)
GobEncode-12 6.52ms ± 1% 6.56ms ± 1% +0.66% (p=0.000 n=20+19)
Gzip-12 318ms ± 1% 319ms ± 1% ~ (p=0.405 n=17+18)
Gunzip-12 42.1ms ± 2% 42.0ms ± 1% ~ (p=0.771 n=20+19)
HTTPClientServer-12 62.6µs ± 1% 62.9µs ± 1% +0.41% (p=0.038 n=20+20)
JSONEncode-12 16.9ms ± 1% 16.9ms ± 1% ~ (p=0.077 n=18+20)
JSONDecode-12 60.7ms ± 1% 62.3ms ± 1% +2.73% (p=0.000 n=20+20)
Mandelbrot200-12 3.86ms ± 1% 3.85ms ± 1% ~ (p=0.084 n=19+20)
GoParse-12 3.75ms ± 2% 3.73ms ± 1% ~ (p=0.107 n=20+19)
RegexpMatchEasy0_32-12 100ns ± 2% 101ns ± 2% +0.97% (p=0.001 n=20+19)
RegexpMatchEasy0_1K-12 342ns ± 2% 332ns ± 2% -2.86% (p=0.000 n=19+19)
RegexpMatchEasy1_32-12 83.2ns ± 2% 82.8ns ± 2% ~ (p=0.108 n=19+20)
RegexpMatchEasy1_1K-12 495ns ± 2% 490ns ± 2% -1.04% (p=0.000 n=18+19)
RegexpMatchMedium_32-12 130ns ± 2% 131ns ± 2% ~ (p=0.291 n=20+20)
RegexpMatchMedium_1K-12 39.3µs ± 1% 39.9µs ± 1% +1.54% (p=0.000 n=18+20)
RegexpMatchHard_32-12 2.02µs ± 1% 2.05µs ± 2% +1.19% (p=0.000 n=19+19)
RegexpMatchHard_1K-12 60.9µs ± 1% 61.5µs ± 1% +0.99% (p=0.000 n=18+18)
Revcomp-12 535ms ± 1% 531ms ± 1% -0.82% (p=0.000 n=17+17)
Template-12 73.0ms ± 1% 74.1ms ± 1% +1.47% (p=0.000 n=20+20)
TimeParse-12 356ns ± 2% 348ns ± 1% -2.30% (p=0.000 n=20+20)
TimeFormat-12 347ns ± 1% 353ns ± 1% +1.68% (p=0.000 n=19+20)
[Geo mean] 62.3µs 62.4µs +0.12%
name old speed new speed delta
GobDecode-12 88.9MB/s ± 1% 88.2MB/s ± 1% -0.81% (p=0.001 n=20+19)
GobEncode-12 118MB/s ± 1% 117MB/s ± 1% -0.66% (p=0.000 n=20+19)
Gzip-12 60.9MB/s ± 1% 60.8MB/s ± 1% ~ (p=0.409 n=17+18)
Gunzip-12 461MB/s ± 2% 462MB/s ± 1% ~ (p=0.765 n=20+19)
JSONEncode-12 115MB/s ± 1% 115MB/s ± 1% ~ (p=0.078 n=18+20)
JSONDecode-12 32.0MB/s ± 1% 31.1MB/s ± 1% -2.65% (p=0.000 n=20+20)
GoParse-12 15.5MB/s ± 2% 15.5MB/s ± 1% ~ (p=0.111 n=20+19)
RegexpMatchEasy0_32-12 318MB/s ± 2% 314MB/s ± 2% -1.27% (p=0.000 n=20+19)
RegexpMatchEasy0_1K-12 2.99GB/s ± 1% 3.08GB/s ± 2% +2.94% (p=0.000 n=19+19)
RegexpMatchEasy1_32-12 385MB/s ± 2% 386MB/s ± 2% ~ (p=0.105 n=19+20)
RegexpMatchEasy1_1K-12 2.07GB/s ± 1% 2.09GB/s ± 2% +1.06% (p=0.000 n=18+19)
RegexpMatchMedium_32-12 7.64MB/s ± 2% 7.61MB/s ± 1% ~ (p=0.179 n=20+20)
RegexpMatchMedium_1K-12 26.1MB/s ± 1% 25.7MB/s ± 1% -1.52% (p=0.000 n=18+20)
RegexpMatchHard_32-12 15.8MB/s ± 1% 15.6MB/s ± 2% -1.18% (p=0.000 n=19+19)
RegexpMatchHard_1K-12 16.8MB/s ± 2% 16.6MB/s ± 1% -0.90% (p=0.000 n=19+18)
Revcomp-12 475MB/s ± 1% 479MB/s ± 1% +0.83% (p=0.000 n=17+17)
Template-12 26.6MB/s ± 1% 26.2MB/s ± 1% -1.45% (p=0.000 n=20+20)
[Geo mean] 99.0MB/s 98.7MB/s -0.32%
Change-Id: I6ea44d7a59aaa6851c64695277ab65645ff9d32e
Reviewed-on: https://go-review.googlesource.com/16070
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>