sync: improve Pool performance
Rewrite indexLocal to achieve higher performance.
Performance results on linux/amd64:
name old time/op new time/op delta
Pool-4 19.1ns ± 2% 10.1ns ± 1% -47.15% (p=0.000 n=10+8)
PoolOverflow-4 3.11µs ± 1% 2.10µs ± 2% -32.66% (p=0.000 n=10+10)
Performance results on linux/386:
name old time/op new time/op delta
Pool-4 20.0ns ± 2% 13.1ns ± 1% -34.59% (p=0.000 n=10+9)
PoolOverflow-4 3.51µs ± 1% 2.49µs ± 0% -28.99% (p=0.000 n=10+8)
Change-Id: I7d57a2d4cd47ec43d09ca1267bde2e3f05a9faa9
Reviewed-on: https://go-review.googlesource.com/40913
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/src/sync/pool.go b/src/sync/pool.go
index 0acdbde..b3fd9d3 100644
--- a/src/sync/pool.go
+++ b/src/sync/pool.go
@@ -241,7 +241,8 @@
}
func indexLocal(l unsafe.Pointer, i int) *poolLocal {
- return &(*[1000000]poolLocal)(l)[i]
+ lp := unsafe.Pointer(uintptr(l) + uintptr(i)*unsafe.Sizeof(poolLocal{}))
+ return (*poolLocal)(lp)
}
// Implemented in runtime.
