diff options
Diffstat (limited to 'src/runtime')
| -rw-r--r-- | src/runtime/proc.go | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/runtime/proc.go b/src/runtime/proc.go index 2bc3c920dc..d1f5088b50 100644 --- a/src/runtime/proc.go +++ b/src/runtime/proc.go @@ -1602,11 +1602,19 @@ func startm(_p_ *p, spinning bool) { // Always runs without a P, so write barriers are not allowed. //go:nowritebarrier func handoffp(_p_ *p) { + // handoffp must start an M in any situation where + // findrunnable would return a G to run on _p_. + // if it has local work, start it straight away if !runqempty(_p_) || sched.runqsize != 0 { startm(_p_, false) return } + // if it has GC work, start it straight away + if gcBlackenEnabled != 0 && gcMarkWorkAvailable(_p_) { + startm(_p_, false) + return + } // no local work, check that there are no spinning/idle M's, // otherwise our help is not required if atomic.Load(&sched.nmspinning)+atomic.Load(&sched.npidle) == 0 && atomic.Cas(&sched.nmspinning, 0, 1) { // TODO: fast atomic @@ -1787,6 +1795,10 @@ func execute(gp *g, inheritTime bool) { func findrunnable() (gp *g, inheritTime bool) { _g_ := getg() + // The conditions here and in handoffp must agree: if + // findrunnable would return a G to run, handoffp must start + // an M. + top: if sched.gcwaiting != 0 { gcstopm() |