diff options
| author | Austin Clements <austin@google.com> | 2016-10-08 18:38:35 -0400 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2016-10-28 14:29:47 +0000 |
| commit | 6da83c6fc006019f6fe0503099d165e19f465b1b (patch) | |
| tree | 155fe589bc74911e73cd403ca40a9254af2feb81 /src/cmd/trace | |
| parent | 640e9169155ea96a6f1156663269dba5babf0632 (diff) | |
| download | go-6da83c6fc006019f6fe0503099d165e19f465b1b.tar.xz | |
runtime, cmd/trace: track goroutines blocked on GC assists
Currently when a goroutine blocks on a GC assist, it emits a generic
EvGoBlock event. Since assist blocking events and, in particular, the
length of the blocked assist queue, are important for diagnosing GC
behavior, this commit adds a new EvGoBlockGC event for blocking on a
GC assist. The trace viewer uses this event to report a "waiting on
GC" count in the "Goroutines" row. This makes sense because, unlike
other blocked goroutines, these goroutines do have work to do, so
being blocked on a GC assist is quite similar to being in the
"runnable" state, which we also report in the trace viewer.
Change-Id: Ic21a326992606b121ea3d3d00110d8d1fdc7a5ef
Reviewed-on: https://go-review.googlesource.com/30704
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Diffstat (limited to 'src/cmd/trace')
| -rw-r--r-- | src/cmd/trace/pprof.go | 2 | ||||
| -rw-r--r-- | src/cmd/trace/trace.go | 14 |
2 files changed, 12 insertions, 4 deletions
diff --git a/src/cmd/trace/pprof.go b/src/cmd/trace/pprof.go index 636d23dc06..3bae15c608 100644 --- a/src/cmd/trace/pprof.go +++ b/src/cmd/trace/pprof.go @@ -62,7 +62,7 @@ func pprofBlock(w io.Writer) error { for _, ev := range events { switch ev.Type { case trace.EvGoBlockSend, trace.EvGoBlockRecv, trace.EvGoBlockSelect, - trace.EvGoBlockSync, trace.EvGoBlockCond: + trace.EvGoBlockSync, trace.EvGoBlockCond, trace.EvGoBlockGC: default: continue } diff --git a/src/cmd/trace/trace.go b/src/cmd/trace/trace.go index 37c14a286f..f92852f2a0 100644 --- a/src/cmd/trace/trace.go +++ b/src/cmd/trace/trace.go @@ -274,6 +274,7 @@ const ( gRunnable gRunning gWaiting + gWaitingGC gStateCount ) @@ -333,6 +334,10 @@ func generateTrace(params *traceParams) (ViewerData, error) { // error in setGStateErr and check it after every event. var setGStateErr error setGState := func(ev *trace.Event, g uint64, oldState, newState gState) { + if oldState == gWaiting && gstates[g] == gWaitingGC { + // For checking, gWaiting counts as any gWaiting*. + oldState = gstates[g] + } if gstates[g] != oldState && setGStateErr == nil { setGStateErr = fmt.Errorf("expected G %d to be in state %d, but got state %d", g, oldState, newState) } @@ -428,6 +433,8 @@ func generateTrace(params *traceParams) (ViewerData, error) { trace.EvGoSleep, trace.EvGoBlock, trace.EvGoBlockSend, trace.EvGoBlockRecv, trace.EvGoBlockSelect, trace.EvGoBlockSync, trace.EvGoBlockCond, trace.EvGoBlockNet: setGState(ev, ev.G, gRunning, gWaiting) + case trace.EvGoBlockGC: + setGState(ev, ev.G, gRunning, gWaitingGC) case trace.EvGoWaiting: setGState(ev, ev.G, gRunnable, gWaiting) case trace.EvGoInSyscall: @@ -536,15 +543,16 @@ func (ctx *traceContext) emitHeapCounters(ev *trace.Event) { } type goroutineCountersArg struct { - Running uint64 - Runnable uint64 + Running uint64 + Runnable uint64 + GCWaiting uint64 } func (ctx *traceContext) emitGoroutineCounters(ev *trace.Event) { if ctx.gtrace { return } - ctx.emit(&ViewerEvent{Name: "Goroutines", Phase: "C", Time: ctx.time(ev), Pid: 1, Arg: &goroutineCountersArg{ctx.gstates[gRunning], ctx.gstates[gRunnable]}}) + ctx.emit(&ViewerEvent{Name: "Goroutines", Phase: "C", Time: ctx.time(ev), Pid: 1, Arg: &goroutineCountersArg{ctx.gstates[gRunning], ctx.gstates[gRunnable], ctx.gstates[gWaitingGC]}}) } type threadCountersArg struct { |