From 29ec902efc0ae53c4435097efdb738667466756c Mon Sep 17 00:00:00 2001 From: Michael Pratt Date: Tue, 16 Nov 2021 11:46:42 -0500 Subject: [PATCH] runtime: get tracking time only when needed casgstatus currently calls nanotime on every casgstatus when tracking, even though the time is only used in some cases. For goroutines making lots of transitions that aren't covered here, this can add a small overhead. Switch to calling nanotime only when necessary. Change-Id: I2617869332e8289ef33dd674d786e44dea09aaba Reviewed-on: https://go-review.googlesource.com/c/go/+/364375 Trust: Michael Pratt Run-TryBot: Michael Pratt Reviewed-by: Michael Knyszek TryBot-Result: Go Bot --- src/runtime/proc.go | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/runtime/proc.go b/src/runtime/proc.go index bf5fa8e4fc..a238ea77f3 100644 --- a/src/runtime/proc.go +++ b/src/runtime/proc.go @@ -980,17 +980,18 @@ func casgstatus(gp *g, oldval, newval uint32) { gp.trackingSeq++ } if gp.tracking { - now := nanotime() if oldval == _Grunnable { // We transitioned out of runnable, so measure how much // time we spent in this state and add it to // runnableTime. + now := nanotime() gp.runnableTime += now - gp.runnableStamp gp.runnableStamp = 0 } if newval == _Grunnable { // We just transitioned into runnable, so record what // time that happened. + now := nanotime() gp.runnableStamp = now } else if newval == _Grunning { // We're transitioning into running, so turn off -- 2.50.0