From bef4efc822794ea2e7310756bc546bf6930fc066 Mon Sep 17 00:00:00 2001 From: Austin Clements Date: Fri, 28 Jul 2017 16:26:51 -0400 Subject: internal/trace: add "per-P" MMU analysis The current MMU analysis considers all Ps together, so if, for example, one of four Ps is blocked, mutator utilization is 75%. However, this is less useful for understanding the impact on individual goroutines because that one blocked goroutine could be blocked for a very long time, but we still appear to have good utilization. Hence, this introduces a new flag that does a "per-P" analysis where the utilization of each P is considered independently. The MMU is then the combination of the MMU for each P's utilization function. Change-Id: Id67b980d4d82b511d28300cdf92ccbb5ae8f0c78 Reviewed-on: https://go-review.googlesource.com/c/60797 Run-TryBot: Austin Clements TryBot-Result: Gobot Gobot Reviewed-by: Hyang-Ah Hana Kim --- src/cmd/trace/mmu.go | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'src/cmd/trace') diff --git a/src/cmd/trace/mmu.go b/src/cmd/trace/mmu.go index 2a07be4ba2..d3b6768686 100644 --- a/src/cmd/trace/mmu.go +++ b/src/cmd/trace/mmu.go @@ -27,12 +27,12 @@ func init() { var mmuCache struct { init sync.Once - util []trace.MutatorUtil + util [][]trace.MutatorUtil mmuCurve *trace.MMUCurve err error } -func getMMUCurve() ([]trace.MutatorUtil, *trace.MMUCurve, error) { +func getMMUCurve() ([][]trace.MutatorUtil, *trace.MMUCurve, error) { mmuCache.init.Do(func() { tr, err := parseTrace() if err != nil { @@ -69,7 +69,16 @@ func httpMMUPlot(w http.ResponseWriter, r *http.Request) { // Cover six orders of magnitude. xMax := xMin * 1e6 // But no more than the length of the trace. - if maxMax := time.Duration(mu[len(mu)-1].Time - mu[0].Time); xMax > maxMax { + minEvent, maxEvent := mu[0][0].Time, mu[0][len(mu[0])-1].Time + for _, mu1 := range mu[1:] { + if mu1[0].Time < minEvent { + minEvent = mu1[0].Time + } + if mu1[len(mu1)-1].Time > maxEvent { + maxEvent = mu1[len(mu1)-1].Time + } + } + if maxMax := time.Duration(maxEvent - minEvent); xMax > maxMax { xMax = maxMax } // Compute MMU curve. -- cgit v1.3