mirror of
https://github.com/golang/go
synced 2024-11-05 18:26:10 -07:00
1fa7029425
Combine NoScan allocations < 16 bytes into a single memory block.
Reduces number of allocations on json/garbage benchmarks by 10+%.
json-1
allocated 8039872 7949194 -1.13%
allocs 105774 93776 -11.34%
cputime 156200000 100700000 -35.53%
gc-pause-one 4908873 3814853 -22.29%
gc-pause-total 2748969 2899288 +5.47%
rss 52674560 43560960 -17.30%
sys-gc 3796976 3256304 -14.24%
sys-heap 43843584 35192832 -19.73%
sys-other 5589312 5310784 -4.98%
sys-stack 393216 393216 +0.00%
sys-total 53623088 44153136 -17.66%
time 156193436 100886714 -35.41%
virtual-mem 256548864 256540672 -0.00%
garbage-1
allocated 2996885 2932982 -2.13%
allocs 62904 55200 -12.25%
cputime 17470000 17400000 -0.40%
gc-pause-one 932757485 925806143 -0.75%
gc-pause-total 4663787 4629030 -0.75%
rss 1151074304 1133670400 -1.51%
sys-gc 66068352 65085312 -1.49%
sys-heap 1039728640 1024065536 -1.51%
sys-other 38038208 37485248 -1.45%
sys-stack 8650752 8781824 +1.52%
sys-total 1152485952 1135417920 -1.48%
time 17478088 17418005 -0.34%
virtual-mem 1343709184 1324204032 -1.45%
LGTM=iant, bradfitz
R=golang-codereviews, dave, iant, rsc, bradfitz
CC=golang-codereviews, khr
https://golang.org/cl/38750047
63 lines
1.5 KiB
Go
63 lines
1.5 KiB
Go
// run
|
|
|
|
// Copyright 2014 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// Test finalizers work for tiny (combined) allocations.
|
|
|
|
package main
|
|
|
|
import (
|
|
"runtime"
|
|
"sync/atomic"
|
|
"time"
|
|
)
|
|
|
|
func main() {
|
|
// Does not work on 32-bits due to partially conservative GC.
|
|
// Try to enable when we have fully precise GC.
|
|
if runtime.GOARCH != "amd64" {
|
|
return
|
|
}
|
|
// Likewise for gccgo.
|
|
if runtime.Compiler == "gccgo" {
|
|
return
|
|
}
|
|
N := int32(100)
|
|
count := N
|
|
done := make([]bool, N)
|
|
for i := int32(0); i < N; i++ {
|
|
x := i // subject to tiny alloc
|
|
// the closure must be big enough to be combined
|
|
runtime.SetFinalizer(&x, func(p *int32) {
|
|
// Check that p points to the correct subobject of the tiny allocation.
|
|
// It's a bit tricky, because we can't capture another variable
|
|
// with the expected value (it would be combined as well).
|
|
if *p < 0 || *p >= N {
|
|
println("got", *p)
|
|
panic("corrupted")
|
|
}
|
|
if done[*p] {
|
|
println("got", *p)
|
|
panic("already finalized")
|
|
}
|
|
done[*p] = true
|
|
atomic.AddInt32(&count, -1)
|
|
})
|
|
}
|
|
for i := 0; i < 4; i++ {
|
|
runtime.GC()
|
|
time.Sleep(10 * time.Millisecond)
|
|
}
|
|
// Some of the finalizers may not be executed,
|
|
// if the outermost allocations are combined with something persistent.
|
|
// Currently 4 int32's are combined into a 16-byte block,
|
|
// ensure that most of them are finalized.
|
|
if count >= N/4 {
|
|
println(count, "out of", N, "finalizer are not called")
|
|
panic("not all finalizers are called")
|
|
}
|
|
}
|
|
|