[dev.link] all: merge branch 'master' into dev.linkdev.link

Clean merge.

Change-Id: Ia7b2808bc649790198d34c226a61d9e569084dc5

1 files changed, 2 insertions, 76 deletions

diff --git a/src/runtime/mgcwork.go b/src/runtime/mgcwork.go
index 46101657d5..b3a068661e 100644
--- a/src/runtime/mgcwork.go
+++ b/src/runtime/mgcwork.go
@@ -22,13 +22,6 @@ const (
 	workbufAlloc = 32 << 10
 )
 
-// throwOnGCWork causes any operations that add pointers to a gcWork
-// buffer to throw.
-//
-// TODO(austin): This is a temporary debugging measure for issue
-// #27993. To be removed before release.
-var throwOnGCWork bool
-
 func init() {
 	if workbufAlloc%pageSize != 0 || workbufAlloc%_WorkbufSize != 0 {
 		throw("bad workbufAlloc")
@@ -93,17 +86,6 @@ type gcWork struct {
 	// termination check. Specifically, this indicates that this
 	// gcWork may have communicated work to another gcWork.
 	flushedWork bool
-
-	// pauseGen causes put operations to spin while pauseGen ==
-	// gcWorkPauseGen if debugCachedWork is true.
-	pauseGen uint32
-
-	// putGen is the pauseGen of the last putGen.
-	putGen uint32
-
-	// pauseStack is the stack at which this P was paused if
-	// debugCachedWork is true.
-	pauseStack [16]uintptr
 }
 
 // Most of the methods of gcWork are go:nowritebarrierrec because the
@@ -122,60 +104,10 @@ func (w *gcWork) init() {
 	w.wbuf2 = wbuf2
 }
 
-func (w *gcWork) checkPut(ptr uintptr, ptrs []uintptr) {
-	if debugCachedWork {
-		alreadyFailed := w.putGen == w.pauseGen
-		w.putGen = w.pauseGen
-		if !canPreemptM(getg().m) {
-			// If we were to spin, the runtime may
-			// deadlock. Since we can't be preempted, the
-			// spin could prevent gcMarkDone from
-			// finishing the ragged barrier, which is what
-			// releases us from the spin.
-			return
-		}
-		for atomic.Load(&gcWorkPauseGen) == w.pauseGen {
-		}
-		if throwOnGCWork {
-			printlock()
-			if alreadyFailed {
-				println("runtime: checkPut already failed at this generation")
-			}
-			println("runtime: late gcWork put")
-			if ptr != 0 {
-				gcDumpObject("ptr", ptr, ^uintptr(0))
-			}
-			for _, ptr := range ptrs {
-				gcDumpObject("ptrs", ptr, ^uintptr(0))
-			}
-			println("runtime: paused at")
-			for _, pc := range w.pauseStack {
-				if pc == 0 {
-					break
-				}
-				f := findfunc(pc)
-				if f.valid() {
-					// Obviously this doesn't
-					// relate to ancestor
-					// tracebacks, but this
-					// function prints what we
-					// want.
-					printAncestorTracebackFuncInfo(f, pc)
-				} else {
-					println("\tunknown PC ", hex(pc), "\n")
-				}
-			}
-			throw("throwOnGCWork")
-		}
-	}
-}
-
 // put enqueues a pointer for the garbage collector to trace.
 // obj must point to the beginning of a heap object or an oblet.
 //go:nowritebarrierrec
 func (w *gcWork) put(obj uintptr) {
-	w.checkPut(obj, nil)
-
 	flushed := false
 	wbuf := w.wbuf1
 	// Record that this may acquire the wbufSpans or heap lock to
@@ -214,8 +146,6 @@ func (w *gcWork) put(obj uintptr) {
 // otherwise it returns false and the caller needs to call put.
 //go:nowritebarrierrec
 func (w *gcWork) putFast(obj uintptr) bool {
-	w.checkPut(obj, nil)
-
 	wbuf := w.wbuf1
 	if wbuf == nil {
 		return false
@@ -237,8 +167,6 @@ func (w *gcWork) putBatch(obj []uintptr) {
 		return
 	}
 
-	w.checkPut(0, obj)
-
 	flushed := false
 	wbuf := w.wbuf1
 	if wbuf == nil {
@@ -360,12 +288,10 @@ func (w *gcWork) balance() {
 		return
 	}
 	if wbuf := w.wbuf2; wbuf.nobj != 0 {
-		w.checkPut(0, wbuf.obj[:wbuf.nobj])
 		putfull(wbuf)
 		w.flushedWork = true
 		w.wbuf2 = getempty()
 	} else if wbuf := w.wbuf1; wbuf.nobj > 4 {
-		w.checkPut(0, wbuf.obj[:wbuf.nobj])
 		w.wbuf1 = handoff(wbuf)
 		w.flushedWork = true // handoff did putfull
 	} else {
@@ -445,7 +371,7 @@ func getempty() *workbuf {
 		}
 		if s == nil {
 			systemstack(func() {
-				s = mheap_.allocManual(workbufAlloc/pageSize, &memstats.gc_sys)
+				s = mheap_.allocManual(workbufAlloc/pageSize, spanAllocWorkBuf)
 			})
 			if s == nil {
 				throw("out of memory")
@@ -547,7 +473,7 @@ func freeSomeWbufs(preemptible bool) bool {
 				break
 			}
 			work.wbufSpans.free.remove(span)
-			mheap_.freeManual(span, &memstats.gc_sys)
+			mheap_.freeManual(span, spanAllocWorkBuf)
 		}
 	})
 	more := !work.wbufSpans.free.isEmpty()