qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-09-28 18:14:29 -06:00
Code Releases Activity

[release-branch.go1.9] runtime: make runtime.GC() trigger GC even if GOGC=off

Browse Source 
Currently, the priority of checks in (gcTrigger).test() puts the
gcpercent<0 test above gcTriggerCycle, which is used for runtime.GC().
This is an unintentional change from 1.8 and before, where
runtime.GC() triggered a GC even if GOGC=off.

Fix this by rearranging the priority so the gcTriggerCycle test
executes even if gcpercent < 0.

Fixes #22023.

Change-Id: I109328d7b643b6824eb9d79061a9e775f0149575
Reviewed-on: https://go-review.googlesource.com/65994
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-on: https://go-review.googlesource.com/70979
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This commit is contained in:
Austin Clements 2017-09-25 14:58:13 -04:00 committed by Russ Cox
parent 0ab99b396d
commit ebfcdef901
2 changed files with 20 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
src/runtime/gc_test.go
View File

@ -499,3 +499,19 @@ func BenchmarkReadMemStats(b *testing.B) {
hugeSink = nil
}
func TestUserForcedGC(t *testing.T) {
// Test that runtime.GC() triggers a GC even if GOGC=off.
defer debug.SetGCPercent(debug.SetGCPercent(-1))
var ms1, ms2 runtime.MemStats
runtime.ReadMemStats(&ms1)
runtime.GC()
runtime.ReadMemStats(&ms2)
if ms1.NumGC == ms2.NumGC {
t.Fatalf("runtime.GC() did not trigger GC")
}
if ms1.NumForcedGC == ms2.NumForcedGC {
t.Fatalf("runtime.GC() was not accounted in NumForcedGC")
}
}

5
src/runtime/mgc.go
View File

@ -1158,7 +1158,7 @@ func (t gcTrigger) test() bool {
if t.kind == gcTriggerAlways {
return true
}
if gcphase != _GCoff || gcpercent < 0 {
if gcphase != _GCoff {
return false
}
switch t.kind {
@ -1169,6 +1169,9 @@ func (t gcTrigger) test() bool {
// own write.
return memstats.heap_live >= memstats.gc_trigger
case gcTriggerTime:
if gcpercent < 0 {
return false
}
lastgc := int64(atomic.Load64(&memstats.last_gc_nanotime))
return lastgc != 0 && t.now-lastgc > forcegcperiod
case gcTriggerCycle: