diff options
Diffstat (limited to 'src/runtime')
| -rw-r--r-- | src/runtime/mgcmark.go | 3 | ||||
| -rw-r--r-- | src/runtime/mgcwork.go | 7 |
2 files changed, 7 insertions, 3 deletions
diff --git a/src/runtime/mgcmark.go b/src/runtime/mgcmark.go index f6452ea133..bdb5888a28 100644 --- a/src/runtime/mgcmark.go +++ b/src/runtime/mgcmark.go @@ -366,9 +366,6 @@ func gcDrain(gcw *gcWork) { } // gcDrainN scans n objects, blackening grey objects. -// -// This MUST be run on the system stack to prevent a stop-the-world -// while this locally holds GC work buffers. //go:nowritebarrier func gcDrainN(gcw *gcWork, n int) { checknocurrentwbuf() diff --git a/src/runtime/mgcwork.go b/src/runtime/mgcwork.go index ecf603a739..f69d6bb6a1 100644 --- a/src/runtime/mgcwork.go +++ b/src/runtime/mgcwork.go @@ -41,8 +41,15 @@ func (wp wbufptr) ptr() *workbuf { // The usual pattern for using gcWork is: // // var gcw gcWork +// disable preemption // .. call gcw.put() to produce and gcw.get() to consume .. // gcw.dispose() +// enable preemption +// +// It's important that any use of gcWork during the mark phase prevent +// the garbage collector from transitioning to mark termination since +// gcWork may locally hold GC work buffers. This can be done by +// disabling preemption (systemstack or acquirem). type gcWork struct { // Invariant: wbuf is never full or empty wbuf wbufptr |