diff options
Diffstat (limited to 'src/runtime/mgcwork.go')
| -rw-r--r-- | src/runtime/mgcwork.go | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/src/runtime/mgcwork.go b/src/runtime/mgcwork.go index ee7eec9ef7..48ac94eecd 100644 --- a/src/runtime/mgcwork.go +++ b/src/runtime/mgcwork.go @@ -55,9 +55,10 @@ func init() { // | Priority | Work queue | Restrictions | Function | // |----------------------------------------------------------| // | 1 | Workbufs | P-local | tryGetObjFast | -// | 2 | Span queue | P-local | tryGetSpan(false) | [greenteagc] +// | 2 | Span queue | P-local | tryGetSpanFast | [greenteagc] // | 3 | Workbufs | None | tryGetObj | -// | 4 | Span queue | None | tryGetSpan(true) | [greenteagc] +// | 4 | Span queue | None | tryGetSpan | [greenteagc] +// | 5 | Span queue | None | tryStealSpan | [greenteagc] // +----------------------------------------------------------+ // // The rationale behind this ordering comes from two insights: @@ -80,6 +81,8 @@ func init() { // gcWork may locally hold GC work buffers. This can be done by // disabling preemption (systemstack or acquirem). type gcWork struct { + id int32 // same ID as the parent P + // wbuf1 and wbuf2 are the primary and secondary work buffers. // // This can be thought of as a stack of both work buffers' @@ -103,7 +106,7 @@ type gcWork struct { // spanq is a queue of spans to process. // // Only used if goexperiment.GreenTeaGC. - spanq localSpanQueue + spanq spanQueue // ptrBuf is a temporary buffer used by span scanning. ptrBuf *[pageSize / goarch.PtrSize]uintptr @@ -318,7 +321,18 @@ func (w *gcWork) dispose() { } w.wbuf2 = nil } - if w.spanq.drain() { + if !w.spanq.empty() { + w.spanq.flush() // Flush any local work. + + // There's globally-visible work now, so make everyone aware of it. + // + // Note that we need to make everyone aware even if flush didn't + // flush any local work. The global work was always visible, but + // the bitmap bit may have been unset. + // + // See the comment in tryStealSpan, which explains how it relies + // on this behavior. + work.spanqMask.set(w.id) w.flushedWork = true } if w.bytesMarked != 0 { |