runtime/metrics: add /sync/mutex/wait/total:seconds metric

This change adds a metric to the runtime/metrics package which tracks
total mutex wait time for sync.Mutex and sync.RWMutex. The purpose of
this metric is to be able to quickly get an idea of the total mutex wait
time.

The implementation of this metric piggybacks off of the existing G
runnable tracking infrastructure, as well as the wait reason set on a G
when it goes into _Gwaiting.

Fixes #49881.

Change-Id: I4691abf64ac3574bec69b4d7d4428b1573130517
Reviewed-on: https://go-review.googlesource.com/c/go/+/427618
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
This commit is contained in:
Michael Anthony Knyszek 2022-08-31 21:34:23 +00:00 committed by Gopher Robot
parent 686b38b5b2
commit 63ceff95fa
7 changed files with 221 additions and 25 deletions

View file

@ -525,6 +525,12 @@ func Getg() *G {
return getg()
}
func GIsWaitingOnMutex(gp *G) bool {
return readgstatus(gp) == _Gwaiting && gp.waitreason.isMutexWait()
}
var CasGStatusAlwaysTrack = &casgstatusAlwaysTrack
//go:noinline
func PanicForTesting(b []byte, i int) byte {
return unexportedPanicForTesting(b, i)
@ -1617,3 +1623,5 @@ func (s *ScavengeIndex) Mark(base, limit uintptr) {
func (s *ScavengeIndex) Clear(ci ChunkIdx) {
s.i.clear(chunkIdx(ci))
}
const GTrackingPeriod = gTrackingPeriod