go/zodb/cache.go · 0e2be3b3b890b25eb66683d137a0e10ca97285c5 · Levin Zimmermann / neoppod

X zodb/cache: Performing GC in separate goroutine was actually a bad idea · 0e2be3b3

Kirill Smelkov authored Jan 08, 2018

Probably channel signalling + goroutine scheduling overhead was taking
too much - see appendix for timings.

Once again - as in 521d3ae5 (X zodb/cache: Also free OCE entries on GC)
we can ignore *Hit/size=0 increase as /size=0 won't happen in practice
and we mostly care about NoHit overhead for which /size=0 also improves.
The HitProc/* increase, as in 521d3ae5, is also withing noise.

---- 8< ----

name old time/op new time/op delta
NoopStorage 56.6ns ± 0% 57.9ns ± 1% +2.36% (p=0.100 n=3+3)
NoopStorage-4 56.9ns ± 1% 57.4ns ± 1% ~ (p=0.200 n=3+3)
CacheStartup 1.97µs ± 3% 2.13µs ±16% ~ (p=0.600 n=3+3)
CacheStartup-4 1.29µs ± 4% 1.29µs ± 4% ~ (p=1.000 n=3+3)
CacheNoHit/size=0 1.34µs ± 1% 0.68µs ± 1% -49.43% (p=0.100 n=3+3)
CacheNoHit/size=0-4 941ns ± 1% 664ns ± 1% -29.38% (p=0.100 n=3+3)
CacheNoHit/size=16 1.38µs ± 3% 0.79µs ± 0% -42.49% (p=0.100 n=3+3)
CacheNoHit/size=16-4 939ns ± 2% 788ns ± 0% -16.02% (p=0.100 n=3+3)
CacheNoHit/size=128 1.32µs ± 2% 0.80µs ± 0% -39.55% (p=0.100 n=3+3)
CacheNoHit/size=128-4 946ns ± 1% 795ns ± 1% -16.03% (p=0.100 n=3+3)
CacheNoHit/size=512 1.37µs ± 3% 0.82µs ± 0% -40.33% (p=0.100 n=3+3)
CacheNoHit/size=512-4 977ns ± 2% 803ns ± 0% -17.75% (p=0.100 n=3+3)
CacheNoHit/size=4096 1.37µs ± 4% 1.05µs ± 1% -23.03% (p=0.100 n=3+3)
CacheNoHit/size=4096-4 1.07µs ± 0% 0.86µs ± 0% -19.94% (p=0.100 n=3+3)
CacheHit/size=0 164ns ±29% 664ns ± 0% +305.08% (p=0.100 n=3+3)
CacheHit/size=0-4 251ns ± 6% 660ns ± 0% +162.95% (p=0.100 n=3+3)
CacheHit/size=16 120ns ± 1% 123ns ± 4% ~ (p=0.700 n=3+3)
CacheHit/size=16-4 121ns ± 2% 121ns ± 1% ~ (p=1.000 n=3+3)
CacheHit/size=128 123ns ± 1% 124ns ± 1% ~ (p=1.000 n=3+3)
CacheHit/size=128-4 124ns ± 0% 124ns ± 1% ~ (p=1.000 n=3+3)
CacheHit/size=512 125ns ± 0% 126ns ± 1% ~ (p=0.400 n=3+3)
CacheHit/size=512-4 126ns ± 1% 125ns ± 1% ~ (p=0.400 n=3+3)
CacheHit/size=4096 128ns ± 1% 127ns ± 1% ~ (p=1.000 n=3+3)
CacheHit/size=4096-4 128ns ± 1% 128ns ± 1% ~ (p=1.000 n=3+3)
NoopStoragePar 56.5ns ± 0% 59.2ns ± 1% +4.84% (p=0.100 n=3+3)
NoopStoragePar-4 33.1ns ± 3% 31.2ns ± 8% ~ (p=0.400 n=3+3)
CacheStartupPar 2.01µs ±14% 2.04µs ± 6% ~ (p=0.800 n=3+3)
CacheStartupPar-4 1.47µs ± 4% 1.48µs ± 3% ~ (p=1.000 n=3+3)
CacheNoHitPar/size=0 1.35µs ± 3% 0.67µs ± 0% -50.25% (p=0.100 n=3+3)
CacheNoHitPar/size=0-4 1.04µs ± 0% 0.90µs ± 0% -12.83% (p=0.100 n=3+3)
CacheNoHitPar/size=16 1.32µs ± 2% 0.79µs ± 0% -40.36% (p=0.100 n=3+3)
CacheNoHitPar/size=16-4 1.04µs ± 0% 1.03µs ± 0% -1.28% (p=0.100 n=3+3)
CacheNoHitPar/size=128 1.33µs ± 1% 0.80µs ± 0% -40.02% (p=0.100 n=3+3)
CacheNoHitPar/size=128-4 1.03µs ± 1% 1.04µs ± 0% ~ (p=0.400 n=3+3)
CacheNoHitPar/size=512 1.34µs ± 2% 0.82µs ± 0% -38.79% (p=0.100 n=3+3)
CacheNoHitPar/size=512-4 1.07µs ± 2% 1.07µs ± 0% ~ (p=0.600 n=3+3)
CacheNoHitPar/size=4096 1.36µs ± 4% 1.06µs ± 1% -21.87% (p=0.100 n=3+3)
CacheNoHitPar/size=4096-4 1.16µs ± 2% 1.17µs ± 1% ~ (p=0.700 n=3+3)
CacheHitPar/size=0 163ns ± 3% 665ns ± 0% +306.94% (p=0.100 n=3+3)
CacheHitPar/size=0-4 394ns ± 3% 903ns ± 1% +129.08% (p=0.100 n=3+3)
CacheHitPar/size=16 121ns ± 0% 124ns ± 1% +2.20% (p=0.100 n=3+3)
CacheHitPar/size=16-4 213ns ± 0% 217ns ± 1% +2.03% (p=0.100 n=3+3)
CacheHitPar/size=128 124ns ± 1% 125ns ± 0% ~ (p=0.400 n=3+3)
CacheHitPar/size=128-4 208ns ± 0% 215ns ± 1% +3.21% (p=0.100 n=3+3)
CacheHitPar/size=512 126ns ± 1% 127ns ± 1% ~ (p=0.300 n=3+3)
CacheHitPar/size=512-4 205ns ± 0% 241ns ± 0% +17.40% (p=0.100 n=3+3)
CacheHitPar/size=4096 127ns ± 0% 129ns ± 0% +1.57% (p=0.100 n=3+3)
CacheHitPar/size=4096-4 201ns ± 0% 236ns ± 4% +17.58% (p=0.100 n=3+3)
NoopStorageProc 54.8ns ± 0% 56.1ns ± 0% +2.43% (p=0.100 n=3+3)
NoopStorageProc-4 32.6ns ± 4% 37.1ns ±10% +14.02% (p=0.100 n=3+3)
CacheStartupProc 1.91µs ± 7% 1.79µs ± 3% ~ (p=0.400 n=3+3)
CacheStartupProc-4 1.13µs ± 1% 1.08µs ± 7% ~ (p=0.400 n=3+3)
CacheNoHitProc/size=0 1.32µs ± 1% 0.67µs ± 0% -49.38% (p=0.100 n=3+3)
CacheNoHitProc/size=0-4 649ns ± 1% 414ns ±15% -36.23% (p=0.100 n=3+3)
CacheNoHitProc/size=16 1.33µs ± 3% 0.79µs ± 0% -40.23% (p=0.100 n=3+3)
CacheNoHitProc/size=16-4 650ns ± 2% 440ns ± 7% -32.34% (p=0.100 n=3+3)
CacheNoHitProc/size=128 1.31µs ± 5% 0.81µs ± 0% -38.41% (p=0.100 n=3+3)
CacheNoHitProc/size=128-4 663ns ± 1% 467ns ± 8% -29.58% (p=0.100 n=3+3)
CacheNoHitProc/size=512 1.30µs ± 2% 0.83µs ± 1% -35.72% (p=0.100 n=3+3)
CacheNoHitProc/size=512-4 685ns ± 1% 499ns ± 9% -27.12% (p=0.100 n=3+3)
CacheNoHitProc/size=4096 1.35µs ± 3% 1.07µs ± 0% -20.87% (p=0.100 n=3+3)
CacheNoHitProc/size=4096-4 684ns ± 2% 629ns ± 3% -8.04% (p=0.100 n=3+3)
CacheHitProc/size=0 159ns ± 3% 669ns ± 0% +320.75% (p=0.100 n=3+3)
CacheHitProc/size=0-4 75.1ns ±10% 381.0ns ± 2% +407.10% (p=0.100 n=3+3)
CacheHitProc/size=16 120ns ± 1% 121ns ± 1% ~ (p=0.300 n=3+3)
CacheHitProc/size=16-4 58.1ns ± 2% 65.0ns ± 3% +11.94% (p=0.100 n=3+3)
CacheHitProc/size=128 123ns ± 0% 124ns ± 0% +0.81% (p=0.100 n=3+3)
CacheHitProc/size=128-4 57.6ns ± 0% 74.9ns ± 3% +30.05% (p=0.100 n=3+3)
CacheHitProc/size=512 124ns ± 1% 125ns ± 1% ~ (p=0.300 n=3+3)
CacheHitProc/size=512-4 59.4ns ± 1% 71.5ns ± 2% +20.38% (p=0.100 n=3+3)
CacheHitProc/size=4096 127ns ± 0% 132ns ± 6% +3.94% (p=0.100 n=3+3)
CacheHitProc/size=4096-4 64.2ns ± 1% 80.5ns ± 7% +25.34% (p=0.100 n=3+3)

name old alloc/op new alloc/op delta
NoopStorage 0.00B 0.00B ~ (all equal)
NoopStorage-4 0.00B 0.00B ~ (all equal)
CacheStartup 285B ± 0% 285B ± 0% ~ (all equal)
CacheStartup-4 285B ± 0% 285B ± 0% ~ (all equal)
CacheNoHit/size=0 247B ± 2% 152B ± 0% -38.38% (p=0.100 n=3+3)
CacheNoHit/size=0-4 153B ± 0% 152B ± 0% -0.65% (p=0.100 n=3+3)
CacheNoHit/size=16 247B ± 2% 153B ± 0% -37.97% (p=0.100 n=3+3)
CacheNoHit/size=16-4 153B ± 0% 153B ± 0% ~ (p=1.000 n=3+3)
CacheNoHit/size=128 241B ± 1% 153B ± 0% -36.60% (p=0.100 n=3+3)
CacheNoHit/size=128-4 153B ± 0% 153B ± 0% ~ (p=1.000 n=3+3)
CacheNoHit/size=512 245B ± 1% 153B ± 0% -37.64% (p=0.100 n=3+3)
CacheNoHit/size=512-4 154B ± 0% 153B ± 0% -0.65% (p=0.100 n=3+3)
CacheNoHit/size=4096 244B ± 1% 153B ± 0% -37.21% (p=0.100 n=3+3)
CacheNoHit/size=4096-4 155B ± 0% 152B ± 0% -1.72% (p=0.100 n=3+3)
CacheHit/size=0 5.00B ±100% 152.00B ± 0% +2940.00% (p=0.100 n=3+3)
CacheHit/size=0-4 11.0B ± 9% 152.0B ± 0% +1281.82% (p=0.100 n=3+3)
CacheHit/size=16 0.00B 0.00B ~ (all equal)
CacheHit/size=16-4 0.00B 0.00B ~ (all equal)
CacheHit/size=128 0.00B 0.00B ~ (all equal)
CacheHit/size=128-4 0.00B 0.00B ~ (all equal)
CacheHit/size=512 0.00B 0.00B ~ (all equal)
CacheHit/size=512-4 0.00B 0.00B ~ (all equal)
CacheHit/size=4096 0.00B 0.00B ~ (all equal)
CacheHit/size=4096-4 0.00B 0.00B ~ (all equal)
NoopStoragePar 0.00B 0.00B ~ (all equal)
NoopStoragePar-4 0.00B 0.00B ~ (all equal)
CacheStartupPar 285B ± 0% 285B ± 0% ~ (all equal)
CacheStartupPar-4 282B ± 1% 281B ± 0% ~ (p=0.600 n=3+3)
CacheNoHitPar/size=0 247B ± 2% 152B ± 0% -38.38% (p=0.100 n=3+3)
CacheNoHitPar/size=0-4 161B ± 0% 152B ± 0% -5.59% (p=0.100 n=3+3)
CacheNoHitPar/size=16 245B ± 1% 153B ± 0% -37.55% (p=0.100 n=3+3)
CacheNoHitPar/size=16-4 161B ± 0% 155B ± 0% -3.93% (p=0.100 n=3+3)
CacheNoHitPar/size=128 245B ± 2% 153B ± 0% -37.55% (p=0.100 n=3+3)
CacheNoHitPar/size=128-4 162B ± 0% 153B ± 0% -5.36% (p=0.100 n=3+3)
CacheNoHitPar/size=512 246B ± 3% 153B ± 0% -37.89% (p=0.100 n=3+3)
CacheNoHitPar/size=512-4 161B ± 0% 153B ± 0% -4.97% (p=0.100 n=3+3)
CacheNoHitPar/size=4096 244B ± 3% 153B ± 0% -37.38% (p=0.100 n=3+3)
CacheNoHitPar/size=4096-4 164B ± 0% 153B ± 0% -6.71% (p=0.100 n=3+3)
CacheHitPar/size=0 5.00B ±20% 152.00B ± 0% +2940.00% (p=0.100 n=3+3)
CacheHitPar/size=0-4 14.0B ± 7% 152.0B ± 0% +985.71% (p=0.100 n=3+3)
CacheHitPar/size=16 0.00B 0.00B ~ (all equal)
CacheHitPar/size=16-4 0.00B 0.00B ~ (all equal)
CacheHitPar/size=128 0.00B 0.00B ~ (all equal)
CacheHitPar/size=128-4 0.00B 0.00B ~ (all equal)
CacheHitPar/size=512 0.00B 0.00B ~ (all equal)
CacheHitPar/size=512-4 0.00B 0.00B ~ (all equal)
CacheHitPar/size=4096 0.00B 0.00B ~ (all equal)
CacheHitPar/size=4096-4 0.00B 0.00B ~ (all equal)
NoopStorageProc 0.00B 0.00B ~ (all equal)
NoopStorageProc-4 0.00B 0.00B ~ (all equal)
CacheStartupProc 285B ± 0% 285B ± 0% ~ (all equal)
CacheStartupProc-4 285B ± 0% 285B ± 0% ~ (all equal)
CacheNoHitProc/size=0 243B ± 1% 152B ± 0% -37.53% (p=0.100 n=3+3)
CacheNoHitProc/size=0-4 195B ± 1% 152B ± 0% -22.05% (p=0.100 n=3+3)
CacheNoHitProc/size=16 247B ± 2% 153B ± 0% -37.97% (p=0.100 n=3+3)
CacheNoHitProc/size=16-4 194B ± 0% 153B ± 0% -21.27% (p=0.100 n=3+3)
CacheNoHitProc/size=128 242B ± 4% 153B ± 0% -36.78% (p=0.100 n=3+3)
CacheNoHitProc/size=128-4 193B ± 0% 153B ± 0% -20.86% (p=0.100 n=3+3)
CacheNoHitProc/size=512 240B ± 2% 153B ± 0% -36.48% (p=0.100 n=3+3)
CacheNoHitProc/size=512-4 190B ± 1% 153B ± 0% -19.33% (p=0.100 n=3+3)
CacheNoHitProc/size=4096 245B ± 2% 153B ± 0% -37.55% (p=0.100 n=3+3)
CacheNoHitProc/size=4096-4 181B ± 2% 153B ± 0% -15.47% (p=0.100 n=3+3)
CacheHitProc/size=0 4.33B ±15% 152.00B ± 0% +3407.69% (p=0.100 n=3+3)
CacheHitProc/size=0-4 3.33B ±50% 152.00B ± 0% +4460.00% (p=0.100 n=3+3)
CacheHitProc/size=16 0.00B 0.00B ~ (all equal)
CacheHitProc/size=16-4 0.00B 0.00B ~ (all equal)
CacheHitProc/size=128 0.00B 0.00B ~ (all equal)
CacheHitProc/size=128-4 0.00B 0.00B ~ (all equal)
CacheHitProc/size=512 0.00B 0.00B ~ (all equal)
CacheHitProc/size=512-4 0.00B 0.00B ~ (all equal)
CacheHitProc/size=4096 0.00B 0.00B ~ (all equal)
CacheHitProc/size=4096-4 0.00B 0.00B ~ (all equal)

name old allocs/op new allocs/op delta
NoopStorage 0.00 0.00 ~ (all equal)
NoopStorage-4 0.00 0.00 ~ (all equal)
CacheStartup 5.00 ± 0% 5.00 ± 0% ~ (all equal)
CacheStartup-4 5.00 ± 0% 5.00 ± 0% ~ (all equal)
CacheNoHit/size=0 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHit/size=0-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHit/size=16 3.33 ±20% 3.00 ± 0% ~ (p=1.000 n=3+3)
CacheNoHit/size=16-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHit/size=128 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHit/size=128-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHit/size=512 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHit/size=512-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHit/size=4096 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHit/size=4096-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheHit/size=0 0.00 3.00 ± 0% +Inf% (p=0.100 n=3+3)
CacheHit/size=0-4 0.00 3.00 ± 0% +Inf% (p=0.100 n=3+3)
CacheHit/size=16 0.00 0.00 ~ (all equal)
CacheHit/size=16-4 0.00 0.00 ~ (all equal)
CacheHit/size=128 0.00 0.00 ~ (all equal)
CacheHit/size=128-4 0.00 0.00 ~ (all equal)
CacheHit/size=512 0.00 0.00 ~ (all equal)
CacheHit/size=512-4 0.00 0.00 ~ (all equal)
CacheHit/size=4096 0.00 0.00 ~ (all equal)
CacheHit/size=4096-4 0.00 0.00 ~ (all equal)
NoopStoragePar 0.00 0.00 ~ (all equal)
NoopStoragePar-4 0.00 0.00 ~ (all equal)
CacheStartupPar 5.00 ± 0% 5.00 ± 0% ~ (all equal)
CacheStartupPar-4 4.33 ±15% 4.00 ± 0% ~ (p=1.000 n=3+3)
CacheNoHitPar/size=0 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitPar/size=0-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitPar/size=16 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitPar/size=16-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitPar/size=128 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitPar/size=128-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitPar/size=512 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitPar/size=512-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitPar/size=4096 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitPar/size=4096-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheHitPar/size=0 0.00 3.00 ± 0% +Inf% (p=0.100 n=3+3)
CacheHitPar/size=0-4 0.00 3.00 ± 0% +Inf% (p=0.100 n=3+3)
CacheHitPar/size=16 0.00 0.00 ~ (all equal)
CacheHitPar/size=16-4 0.00 0.00 ~ (all equal)
CacheHitPar/size=128 0.00 0.00 ~ (all equal)
CacheHitPar/size=128-4 0.00 0.00 ~ (all equal)
CacheHitPar/size=512 0.00 0.00 ~ (all equal)
CacheHitPar/size=512-4 0.00 0.00 ~ (all equal)
CacheHitPar/size=4096 0.00 0.00 ~ (all equal)
CacheHitPar/size=4096-4 0.00 0.00 ~ (all equal)
NoopStorageProc 0.00 0.00 ~ (all equal)
NoopStorageProc-4 0.00 0.00 ~ (all equal)
CacheStartupProc 5.00 ± 0% 5.00 ± 0% ~ (all equal)
CacheStartupProc-4 5.00 ± 0% 5.00 ± 0% ~ (all equal)
CacheNoHitProc/size=0 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitProc/size=0-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitProc/size=16 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitProc/size=16-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitProc/size=128 3.33 ±20% 3.00 ± 0% ~ (p=1.000 n=3+3)
CacheNoHitProc/size=128-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitProc/size=512 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitProc/size=512-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheNoHitProc/size=4096 3.33 ±20% 3.00 ± 0% ~ (p=1.000 n=3+3)
CacheNoHitProc/size=4096-4 3.00 ± 0% 3.00 ± 0% ~ (all equal)
CacheHitProc/size=0 0.00 3.00 ± 0% +Inf% (p=0.100 n=3+3)
CacheHitProc/size=0-4 0.00 3.00 ± 0% +Inf% (p=0.100 n=3+3)
CacheHitProc/size=16 0.00 0.00 ~ (all equal)
CacheHitProc/size=16-4 0.00 0.00 ~ (all equal)
CacheHitProc/size=128 0.00 0.00 ~ (all equal)
CacheHitProc/size=128-4 0.00 0.00 ~ (all equal)
CacheHitProc/size=512 0.00 0.00 ~ (all equal)
CacheHitProc/size=512-4 0.00 0.00 ~ (all equal)
CacheHitProc/size=4096 0.00 0.00 ~ (all equal)
CacheHitProc/size=4096-4 0.00 0.00 ~ (all equal)

0e2be3b3

cache.go 17.4 KB

Replace cache.go