diff options
Diffstat (limited to 'src/runtime/proc.go')
| -rw-r--r-- | src/runtime/proc.go | 114 |
1 files changed, 54 insertions, 60 deletions
diff --git a/src/runtime/proc.go b/src/runtime/proc.go index 4aeb66c92d..485bd65a9e 100644 --- a/src/runtime/proc.go +++ b/src/runtime/proc.go @@ -2351,6 +2351,11 @@ func handoffp(_p_ *p) { startm(_p_, false) return } + // if there's trace work to do, start it straight away + if (trace.enabled || trace.shutdown) && traceReaderAvailable() { + startm(_p_, false) + return + } // if it has GC work, start it straight away if gcBlackenEnabled != 0 && gcMarkWorkAvailable(_p_) { startm(_p_, false) @@ -2535,7 +2540,9 @@ func execute(gp *g, inheritTime bool) { // Finds a runnable goroutine to execute. // Tries to steal from other P's, get g from local or global queue, poll network. -func findrunnable() (gp *g, inheritTime bool) { +// tryWakeP indicates that the returned goroutine is not normal (GC worker, trace +// reader) so the caller should try to wake a P. +func findRunnable() (gp *g, inheritTime, tryWakeP bool) { _g_ := getg() // The conditions here and in handoffp must agree: if @@ -2552,8 +2559,43 @@ top: runSafePointFn() } + // now and pollUntil are saved for work stealing later, + // which may steal timers. It's important that between now + // and then, nothing blocks, so these numbers remain mostly + // relevant. now, pollUntil, _ := checkTimers(_p_, 0) + // Try to schedule the trace reader. + if trace.enabled || trace.shutdown { + gp = traceReader() + if gp != nil { + casgstatus(gp, _Gwaiting, _Grunnable) + traceGoUnpark(gp, 0) + return gp, false, true + } + } + + // Try to schedule a GC worker. + if gcBlackenEnabled != 0 { + gp = gcController.findRunnableGCWorker(_p_) + if gp != nil { + return gp, false, true + } + } + + // Check the global runnable queue once in a while to ensure fairness. + // Otherwise two goroutines can completely occupy the local runqueue + // by constantly respawning each other. + if _p_.schedtick%61 == 0 && sched.runqsize > 0 { + lock(&sched.lock) + gp = globrunqget(_p_, 1) + unlock(&sched.lock) + if gp != nil { + return gp, false, false + } + } + + // Wake up the finalizer G. if fingwait && fingwake { if gp := wakefing(); gp != nil { ready(gp, 0, true) @@ -2565,7 +2607,7 @@ top: // local runq if gp, inheritTime := runqget(_p_); gp != nil { - return gp, inheritTime + return gp, inheritTime, false } // global runq @@ -2574,7 +2616,7 @@ top: gp := globrunqget(_p_, 0) unlock(&sched.lock) if gp != nil { - return gp, false + return gp, false, false } } @@ -2593,7 +2635,7 @@ top: if trace.enabled { traceGoUnpark(gp, 0) } - return gp, false + return gp, false, false } } @@ -2613,7 +2655,7 @@ top: now = tnow if gp != nil { // Successfully stole. - return gp, inheritTime + return gp, inheritTime, false } if newWork { // There may be new timer or GC work; restart to @@ -2639,7 +2681,7 @@ top: if trace.enabled { traceGoUnpark(gp, 0) } - return gp, false + return gp, false, false } gcController.removeIdleMarkWorker() } @@ -2654,7 +2696,7 @@ top: if trace.enabled { traceGoUnpark(gp, 0) } - return gp, false + return gp, false, false } if otherReady { goto top @@ -2679,7 +2721,7 @@ top: if sched.runqsize != 0 { gp := globrunqget(_p_, 0) unlock(&sched.lock) - return gp, false + return gp, false, false } if releasep() != _p_ { throw("findrunnable: wrong p") @@ -2742,7 +2784,7 @@ top: if trace.enabled { traceGoUnpark(gp, 0) } - return gp, false + return gp, false, false } // Finally, check for timer creation or expiry concurrently with @@ -2800,7 +2842,7 @@ top: if trace.enabled { traceGoUnpark(gp, 0) } - return gp, false + return gp, false, false } if wasSpinning { _g_.m.spinning = true @@ -3147,62 +3189,14 @@ top: pp := _g_.m.p.ptr() pp.preempt = false - if sched.gcwaiting != 0 { - gcstopm() - goto top - } - if pp.runSafePointFn != 0 { - runSafePointFn() - } - - // Sanity check: if we are spinning, the run queue should be empty. + // Safety check: if we are spinning, the run queue should be empty. // Check this before calling checkTimers, as that might call // goready to put a ready goroutine on the local run queue. if _g_.m.spinning && (pp.runnext != 0 || pp.runqhead != pp.runqtail) { throw("schedule: spinning with local work") } - checkTimers(pp, 0) - - var gp *g - var inheritTime bool - - // Normal goroutines will check for need to wakeP in ready, - // but GCworkers and tracereaders will not, so the check must - // be done here instead. - tryWakeP := false - if trace.enabled || trace.shutdown { - gp = traceReader() - if gp != nil { - casgstatus(gp, _Gwaiting, _Grunnable) - traceGoUnpark(gp, 0) - tryWakeP = true - } - } - if gp == nil && gcBlackenEnabled != 0 { - gp = gcController.findRunnableGCWorker(_g_.m.p.ptr()) - if gp != nil { - tryWakeP = true - } - } - if gp == nil { - // Check the global runnable queue once in a while to ensure fairness. - // Otherwise two goroutines can completely occupy the local runqueue - // by constantly respawning each other. - if _g_.m.p.ptr().schedtick%61 == 0 && sched.runqsize > 0 { - lock(&sched.lock) - gp = globrunqget(_g_.m.p.ptr(), 1) - unlock(&sched.lock) - } - } - if gp == nil { - gp, inheritTime = runqget(_g_.m.p.ptr()) - // We can see gp != nil here even if the M is spinning, - // if checkTimers added a local goroutine via goready. - } - if gp == nil { - gp, inheritTime = findrunnable() // blocks until work is available - } + gp, inheritTime, tryWakeP := findRunnable() // blocks until work is available // This thread is going to run a goroutine and is not spinning anymore, // so if it was marked as spinning we need to reset it now and potentially |