diff options
| author | Michael Anthony Knyszek <mknyszek@google.com> | 2025-02-03 16:53:47 +0000 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2025-10-30 10:46:51 -0700 |
| commit | 5b8e85034028906ab0a243399e18fd8b72fe2f76 (patch) | |
| tree | 1da9d7c2ff0ac1917f43f8e882d405c0bfdf1d82 /src/runtime | |
| parent | 251814e5804886923dd1bb07d06c94563a4e1d9b (diff) | |
| download | go-5b8e85034028906ab0a243399e18fd8b72fe2f76.tar.xz | |
runtime: don't track scheduling latency for _Grunning <-> _Gsyscall
The current logic causes much more tracking than necessary, when really
_Grunning and _Gsyscall are both sort of "running" from the perspective
of tracking scheduling latency.
This makes cgo calls and syscalls a little faster in the single-threaded
case, and shows much larger improvement in the multi-threaded case
by removing updates of shared variables (though this parallel
microbenchmark is a little unrealistic, so don't ascribe too much weight
to it).
goos: linux
goarch: amd64
pkg: internal/runtime/cgobench
cpu: AMD EPYC 7B13
│ after.out │ after-2.out │
│ sec/op │ sec/op vs base │
CgoCall-64 35.83n ± 1% 34.69n ± 1% -3.20% (p=0.002 n=6)
CgoCallParallel-64 5.338n ± 1% 1.352n ± 4% -74.67% (p=0.002 n=6)
Change-Id: I2ea494dd5ebbbfb457373549986fbe2fbe318d45
Reviewed-on: https://go-review.googlesource.com/c/go/+/646275
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Diffstat (limited to 'src/runtime')
| -rw-r--r-- | src/runtime/proc.go | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/src/runtime/proc.go b/src/runtime/proc.go index 2ec2f8cfca..53f64e8032 100644 --- a/src/runtime/proc.go +++ b/src/runtime/proc.go @@ -1316,8 +1316,9 @@ func casgstatus(gp *g, oldval, newval uint32) { }) } - if oldval == _Grunning { - // Track every gTrackingPeriod time a goroutine transitions out of running. + if (oldval == _Grunning || oldval == _Gsyscall) && (newval != _Grunning && newval != _Gsyscall) { + // Track every gTrackingPeriod time a goroutine transitions out of _Grunning or _Gsyscall. + // Do not track _Grunning <-> _Gsyscall transitions, since they're two very similar states. if casgstatusAlwaysTrack || gp.trackingSeq%gTrackingPeriod == 0 { gp.tracking = true } |