diff --git a/src/runtime/mgc.go b/src/runtime/mgc.go
index 94301c6dc7..df8b4536fa 100644
--- a/src/runtime/mgc.go
+++ b/src/runtime/mgc.go
@@ -1555,8 +1555,8 @@ func gcMark(start_time int64) {
 
 	gchelperstart()
 
-	var gcw gcWork
-	gcDrain(&gcw, gcDrainBlock)
+	gcw := &getg().m.p.ptr().gcw
+	gcDrain(gcw, gcDrainBlock)
 	gcw.dispose()
 
 	gcMarkRootCheck()
@@ -1798,8 +1798,8 @@ func gchelper() {
 
 	// Parallel mark over GC roots and heap
 	if gcphase == _GCmarktermination {
-		var gcw gcWork
-		gcDrain(&gcw, gcDrainBlock) // blocks in getfull
+		gcw := &_g_.m.p.ptr().gcw
+		gcDrain(gcw, gcDrainBlock) // blocks in getfull
 		gcw.dispose()
 	}
 
diff --git a/src/runtime/mgcwork.go b/src/runtime/mgcwork.go
index e97039bed6..35bc12db22 100644
--- a/src/runtime/mgcwork.go
+++ b/src/runtime/mgcwork.go
@@ -44,14 +44,6 @@ func (wp wbufptr) ptr() *workbuf {
 //
 // A gcWork can be used on the stack as follows:
 //
-//     var gcw gcWork
-//     disable preemption
-//     .. call gcw.put() to produce and gcw.get() to consume ..
-//     gcw.dispose()
-//     enable preemption
-//
-// Or from the per-P gcWork cache:
-//
 //     (preemption must be disabled)
 //     gcw := &getg().m.p.ptr().gcw
 //     .. call gcw.put() to produce and gcw.get() to consume ..