mirror of
https://github.com/golang/go
synced 2024-09-05 16:04:50 +00:00
runtime: implement runqdrain() for GC mark worker goroutines
Change-Id: Ida44a2e07f277bee8806538ecee4beee3474cf3d Reviewed-on: https://go-review.googlesource.com/c/go/+/310149 Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Ian Lance Taylor <iant@golang.org> Trust: Michael Pratt <mpratt@google.com> Trust: Ian Lance Taylor <iant@golang.org> Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Go Bot <gobot@golang.org>
This commit is contained in:
parent
77860ad280
commit
fbb600b283
|
@ -1273,15 +1273,11 @@ func gcBgMarkWorker() {
|
|||
// everything out of the run
|
||||
// queue so it can run
|
||||
// somewhere else.
|
||||
lock(&sched.lock)
|
||||
for {
|
||||
gp, _ := runqget(pp)
|
||||
if gp == nil {
|
||||
break
|
||||
}
|
||||
globrunqput(gp)
|
||||
if drainQ, n := runqdrain(pp); n > 0 {
|
||||
lock(&sched.lock)
|
||||
globrunqputbatch(&drainQ, int32(n))
|
||||
unlock(&sched.lock)
|
||||
}
|
||||
unlock(&sched.lock)
|
||||
}
|
||||
// Go back to draining, this time
|
||||
// without preemption.
|
||||
|
|
|
@ -5911,6 +5911,44 @@ func runqget(_p_ *p) (gp *g, inheritTime bool) {
|
|||
}
|
||||
}
|
||||
|
||||
// runqdrain drains the local runnable queue of _p_ and returns all g's in it.
|
||||
// Executed only by the owner P.
|
||||
func runqdrain(_p_ *p) (drainQ gQueue, n uint32) {
|
||||
var getNext bool
|
||||
oldNext := _p_.runnext
|
||||
if oldNext != 0 && _p_.runnext.cas(oldNext, 0) {
|
||||
drainQ.pushBack(oldNext.ptr())
|
||||
n++
|
||||
getNext = true
|
||||
}
|
||||
|
||||
for {
|
||||
h := atomic.LoadAcq(&_p_.runqhead) // load-acquire, synchronize with other consumers
|
||||
t := _p_.runqtail
|
||||
qn := t - h
|
||||
if qn == 0 {
|
||||
return
|
||||
}
|
||||
for i := uint32(0); i < qn; i++ {
|
||||
gp := _p_.runq[(h+i)%uint32(len(_p_.runq))].ptr()
|
||||
drainQ.pushBack(gp)
|
||||
}
|
||||
if atomic.CasRel(&_p_.runqhead, h, h+qn) { // cas-release, commits consume
|
||||
n += qn
|
||||
return
|
||||
}
|
||||
|
||||
// Clean up if it failed to drain _p_ in this round and start over until it succeed.
|
||||
drainQ = gQueue{}
|
||||
n = 0
|
||||
// Push the prior old _p_.runnext back into drainQ.
|
||||
if getNext {
|
||||
drainQ.pushBack(oldNext.ptr())
|
||||
n++
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Grabs a batch of goroutines from _p_'s runnable queue into batch.
|
||||
// Batch is a ring buffer starting at batchHead.
|
||||
// Returns number of grabbed goroutines.
|
||||
|
|
|
@ -622,6 +622,9 @@ type p struct {
|
|||
// unit and eliminates the (potentially large) scheduling
|
||||
// latency that otherwise arises from adding the ready'd
|
||||
// goroutines to the end of the run queue.
|
||||
//
|
||||
// Note that while other P's may atomically CAS this to zero,
|
||||
// only the owner P can CAS it to a valid G.
|
||||
runnext guintptr
|
||||
|
||||
// Available G's (status == Gdead)
|
||||
|
|
Loading…
Reference in a new issue