runtime: add lock rank partial order edge sweep -> mspanSpecial

This change adds a missing partial order edge. The edge captures the
case where the background sweeper handles some specials (i.e. finalizers
or memory profile sampling) and is otherwise correct.

Fixes #42472.

Change-Id: Ic45f6cc1635fd3d6bc6c91ff6f64d436088cef33
Reviewed-on: https://go-review.googlesource.com/c/go/+/268857
Trust: Michael Knyszek <mknyszek@google.com>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>

diff --git a/src/runtime/lockrank.go b/src/runtime/lockrank.go
index 0a52e8ed3dd49b007812c77e88384e5feac20729..5fb7f08c44d7163a0a305a19e91ddd69fad86771 100644 (file)
--- a/src/runtime/lockrank.go
+++ b/src/runtime/lockrank.go
@@ -213,7 +213,7 @@ var lockPartialOrder [][]lockRank = [][]lockRank{
        lockRankNotifyList:    {},
        lockRankTraceBuf:      {lockRankSysmon, lockRankScavenge},
        lockRankTraceStrings:  {lockRankTraceBuf},
-       lockRankMspanSpecial:  {lockRankSysmon, lockRankScavenge, lockRankAssistQueue, lockRankCpuprof, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankHchan, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings},
+       lockRankMspanSpecial:  {lockRankSysmon, lockRankScavenge, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankHchan, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings},
        lockRankProf:          {lockRankSysmon, lockRankScavenge, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankHchan},
        lockRankGcBitsArenas:  {lockRankSysmon, lockRankScavenge, lockRankAssistQueue, lockRankCpuprof, lockRankSched, lockRankAllg, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankHchan},
        lockRankRoot:          {},