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runtime: remove wbshadow mode
The write barrier shadow heap was very useful for developing the write barriers initially, but it's no longer used, clunky, and dragging the rest of the implementation down. The gccheckmark mode will find bugs due to missed barriers when they result in missed marks; wbshadow mode found the missed barriers more aggressively, but it required an entire separate copy of the heap. The gccheckmark mode requires no extra memory, making it more useful in practice. Compared to previous CL: name old mean new mean delta BinaryTree17 5.91s × (0.96,1.06) 5.72s × (0.97,1.03) -3.12% (p=0.000) Fannkuch11 4.32s × (1.00,1.00) 4.36s × (1.00,1.00) +0.91% (p=0.000) FmtFprintfEmpty 89.0ns × (0.93,1.10) 86.6ns × (0.96,1.11) ~ (p=0.077) FmtFprintfString 298ns × (0.98,1.06) 283ns × (0.99,1.04) -4.90% (p=0.000) FmtFprintfInt 286ns × (0.98,1.03) 283ns × (0.98,1.04) -1.09% (p=0.032) FmtFprintfIntInt 498ns × (0.97,1.06) 480ns × (0.99,1.02) -3.65% (p=0.000) FmtFprintfPrefixedInt 408ns × (0.98,1.02) 396ns × (0.99,1.01) -3.00% (p=0.000) FmtFprintfFloat 587ns × (0.98,1.01) 562ns × (0.99,1.01) -4.34% (p=0.000) FmtManyArgs 1.94µs × (0.99,1.02) 1.89µs × (0.99,1.01) -2.85% (p=0.000) GobDecode 15.8ms × (0.98,1.03) 15.7ms × (0.99,1.02) ~ (p=0.251) GobEncode 12.0ms × (0.96,1.09) 11.8ms × (0.98,1.03) -1.87% (p=0.024) Gzip 648ms × (0.99,1.01) 647ms × (0.99,1.01) ~ (p=0.688) Gunzip 143ms × (1.00,1.01) 143ms × (1.00,1.01) ~ (p=0.203) HTTPClientServer 90.3µs × (0.98,1.01) 89.1µs × (0.99,1.02) -1.30% (p=0.000) JSONEncode 31.6ms × (0.99,1.01) 31.7ms × (0.98,1.02) ~ (p=0.219) JSONDecode 107ms × (1.00,1.01) 111ms × (0.99,1.01) +3.58% (p=0.000) Mandelbrot200 6.03ms × (1.00,1.01) 6.01ms × (1.00,1.00) ~ (p=0.077) GoParse 6.53ms × (0.99,1.03) 6.54ms × (0.99,1.02) ~ (p=0.585) RegexpMatchEasy0_32 161ns × (1.00,1.01) 161ns × (0.98,1.05) ~ (p=0.948) RegexpMatchEasy0_1K 541ns × (0.99,1.01) 559ns × (0.98,1.01) +3.32% (p=0.000) RegexpMatchEasy1_32 138ns × (1.00,1.00) 137ns × (0.99,1.01) -0.55% (p=0.001) RegexpMatchEasy1_1K 887ns × (0.99,1.01) 878ns × (0.99,1.01) -0.98% (p=0.000) RegexpMatchMedium_32 253ns × (0.99,1.01) 252ns × (0.99,1.01) -0.39% (p=0.001) RegexpMatchMedium_1K 72.8µs × (1.00,1.00) 72.7µs × (1.00,1.00) ~ (p=0.485) RegexpMatchHard_32 3.85µs × (1.00,1.01) 3.85µs × (1.00,1.01) ~ (p=0.283) RegexpMatchHard_1K 117µs × (1.00,1.01) 117µs × (1.00,1.00) ~ (p=0.175) Revcomp 922ms × (0.97,1.08) 903ms × (0.98,1.05) -2.15% (p=0.021) Template 126ms × (0.99,1.01) 126ms × (0.99,1.01) ~ (p=0.943) TimeParse 628ns × (0.99,1.01) 634ns × (0.99,1.01) +0.92% (p=0.000) TimeFormat 668ns × (0.99,1.01) 698ns × (0.98,1.03) +4.53% (p=0.000) It's nice that the microbenchmarks are the ones helped the most, because those were the ones hurt the most by the conversion from 4-bit to 2-bit heap bitmaps. This CL brings the overall effect of that process to (compared to CL 9706 patch set 1): name old mean new mean delta BinaryTree17 5.87s × (0.94,1.09) 5.72s × (0.97,1.03) -2.57% (p=0.011) Fannkuch11 4.32s × (1.00,1.00) 4.36s × (1.00,1.00) +0.87% (p=0.000) FmtFprintfEmpty 89.1ns × (0.95,1.16) 86.6ns × (0.96,1.11) ~ (p=0.090) FmtFprintfString 283ns × (0.98,1.02) 283ns × (0.99,1.04) ~ (p=0.681) FmtFprintfInt 284ns × (0.98,1.04) 283ns × (0.98,1.04) ~ (p=0.620) FmtFprintfIntInt 486ns × (0.98,1.03) 480ns × (0.99,1.02) -1.27% (p=0.002) FmtFprintfPrefixedInt 400ns × (0.99,1.02) 396ns × (0.99,1.01) -0.84% (p=0.001) FmtFprintfFloat 566ns × (0.99,1.01) 562ns × (0.99,1.01) -0.80% (p=0.000) FmtManyArgs 1.91µs × (0.99,1.02) 1.89µs × (0.99,1.01) -1.10% (p=0.000) GobDecode 15.5ms × (0.98,1.05) 15.7ms × (0.99,1.02) +1.55% (p=0.005) GobEncode 11.9ms × (0.97,1.03) 11.8ms × (0.98,1.03) -0.97% (p=0.048) Gzip 648ms × (0.99,1.01) 647ms × (0.99,1.01) ~ (p=0.627) Gunzip 143ms × (1.00,1.00) 143ms × (1.00,1.01) ~ (p=0.482) HTTPClientServer 89.2µs × (0.99,1.02) 89.1µs × (0.99,1.02) ~ (p=0.740) JSONEncode 32.3ms × (0.97,1.06) 31.7ms × (0.98,1.02) -1.95% (p=0.002) JSONDecode 106ms × (0.99,1.01) 111ms × (0.99,1.01) +4.22% (p=0.000) Mandelbrot200 6.02ms × (1.00,1.00) 6.01ms × (1.00,1.00) ~ (p=0.417) GoParse 6.57ms × (0.97,1.06) 6.54ms × (0.99,1.02) ~ (p=0.404) RegexpMatchEasy0_32 162ns × (1.00,1.00) 161ns × (0.98,1.05) ~ (p=0.088) RegexpMatchEasy0_1K 561ns × (0.99,1.02) 559ns × (0.98,1.01) -0.47% (p=0.034) RegexpMatchEasy1_32 145ns × (0.95,1.04) 137ns × (0.99,1.01) -5.56% (p=0.000) RegexpMatchEasy1_1K 864ns × (0.99,1.04) 878ns × (0.99,1.01) +1.57% (p=0.000) RegexpMatchMedium_32 255ns × (0.99,1.04) 252ns × (0.99,1.01) -1.43% (p=0.001) RegexpMatchMedium_1K 73.9µs × (0.98,1.04) 72.7µs × (1.00,1.00) -1.55% (p=0.004) RegexpMatchHard_32 3.92µs × (0.98,1.04) 3.85µs × (1.00,1.01) -1.80% (p=0.003) RegexpMatchHard_1K 120µs × (0.98,1.04) 117µs × (1.00,1.00) -2.13% (p=0.001) Revcomp 936ms × (0.95,1.08) 903ms × (0.98,1.05) -3.58% (p=0.002) Template 130ms × (0.98,1.04) 126ms × (0.99,1.01) -2.98% (p=0.000) TimeParse 638ns × (0.98,1.05) 634ns × (0.99,1.01) ~ (p=0.198) TimeFormat 674ns × (0.99,1.01) 698ns × (0.98,1.03) +3.69% (p=0.000) Change-Id: Ia0e9b50b1d75a3c0c7556184cd966305574fe07c Reviewed-on: https://go-review.googlesource.com/9706 Reviewed-by: Rick Hudson <rlh@golang.org>
This commit is contained in:
Russ Cox
parent
54af9a3ba5
commit
1635ab7dfe
10 changed files with 2 additions and 272 deletions
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@ -188,16 +188,6 @@ func newdefer(siz int32) *_defer {
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d = (*_defer)(mallocgc(total, deferType, 0))
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}
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d.siz = siz
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if mheap_.shadow_enabled {
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// This memory will be written directly, with no write barrier,
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// and then scanned like stacks during collection.
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// Unlike real stacks, it is from heap spans, so mark the
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// shadow as explicitly unusable.
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p := deferArgs(d)
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for i := uintptr(0); i+ptrSize <= uintptr(siz); i += ptrSize {
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writebarrierptr_noshadow((*uintptr)(add(p, i)))
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}
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}
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gp := mp.curg
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d.link = gp._defer
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gp._defer = d
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@ -214,12 +204,6 @@ func freedefer(d *_defer) {
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if d.fn != nil {
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freedeferfn()
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}
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if mheap_.shadow_enabled {
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// Undo the marking in newdefer.
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systemstack(func() {
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clearshadow(uintptr(deferArgs(d)), uintptr(d.siz))
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})
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}
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sc := deferclass(uintptr(d.siz))
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if sc < uintptr(len(p{}.deferpool)) {
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mp := acquirem()
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