runtime: add a lock partial order edge (assistQueue -> mspanSpecial)

From interesting stack trace from GC assist through memory profiling to
addspecial().

Fixes #39022

Change-Id: Ia0506b820fe29ae91490b61c4e9c2fffcad9f7d6
Reviewed-on: https://go-review.googlesource.com/c/go/+/233599
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

diff --git a/src/runtime/lockrank.go b/src/runtime/lockrank.go
index 899c4e2e852732ecb46ceb6ae76869e15d87b76b..d97afac6a2ec5edbf3da249c71df56d57a21392e 100644 (file)
--- a/src/runtime/lockrank.go
+++ b/src/runtime/lockrank.go
@@ -214,7 +214,7 @@ var lockPartialOrder [][]lockRank = [][]lockRank{
        lockRankNotifyList:    {},
        lockRankTraceBuf:      {lockRankScavenge},
        lockRankTraceStrings:  {lockRankTraceBuf},
-       lockRankMspanSpecial:  {lockRankScavenge, lockRankCpuprof, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankHchan, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings},
+       lockRankMspanSpecial:  {lockRankScavenge, lockRankAssistQueue, lockRankCpuprof, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankHchan, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings},
        lockRankProf:          {lockRankScavenge, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankHchan},
        lockRankGcBitsArenas:  {lockRankScavenge, lockRankAssistQueue, lockRankCpuprof, lockRankSched, lockRankAllg, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankHchan},
        lockRankRoot:          {},