From: Austin Clements <austin@google.com>
Date: Fri, 20 Mar 2020 19:52:43 +0000 (-0400)
Subject: [dev.link] cmd/link: record per-phase memory profile
X-Git-Tag: go1.15beta1~679^2~54
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=105053fa19eba7f9761e1fdf1007905051583d44;p=gostls13.git

[dev.link] cmd/link: record per-phase memory profile

We already have an option to record per-phase CPU profiles. If we're
in "mem" benchmark mode, then it also makes sense to collect a heap
profile of the live heap at the end of a phase. This CL adds that
profile and changes the extensions of the profiles to "cpuprof" and
"memprof" to make the distinction clear.

Change-Id: Ia05b7fa18bccad954a875f7a55d9cff5ad8dfaaf
Reviewed-on: https://go-review.googlesource.com/c/go/+/224617
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
---

diff --git a/src/cmd/link/internal/benchmark/bench.go b/src/cmd/link/internal/benchmark/bench.go
index 52f98269a1..7b8492ec85 100644
--- a/src/cmd/link/internal/benchmark/bench.go
+++ b/src/cmd/link/internal/benchmark/bench.go
@@ -116,7 +116,7 @@ func (m *Metrics) Start(name string) {
 	m.curMark = &mark{name: name}
 	// Unlikely we need to a GC here, as one was likely just done in closeMark.
 	if m.shouldPProf() {
-		f, err := os.Create(makePProfFilename(m.filebase, name))
+		f, err := os.Create(makePProfFilename(m.filebase, name, "cpuprof"))
 		if err != nil {
 			panic(err)
 		}
@@ -143,6 +143,25 @@ func (m *Metrics) closeMark() {
 		pprof.StopCPUProfile()
 		m.pprofFile.Close()
 		m.pprofFile = nil
+		if m.gc == GC {
+			// Collect a profile of the live heap. Do a
+			// second GC to force sweep completion so we
+			// get a complete snapshot of the live heap at
+			// the end of this phase.
+			runtime.GC()
+			f, err := os.Create(makePProfFilename(m.filebase, m.curMark.name, "memprof"))
+			if err != nil {
+				panic(err)
+			}
+			err = pprof.WriteHeapProfile(f)
+			if err != nil {
+				panic(err)
+			}
+			err = f.Close()
+			if err != nil {
+				panic(err)
+			}
+		}
 	}
 	m.marks = append(m.marks, m.curMark)
 	m.curMark = nil
@@ -171,6 +190,6 @@ func makeBenchString(name string) string {
 	return string(ret)
 }
 
-func makePProfFilename(filebase, name string) string {
-	return fmt.Sprintf("%s_%s.profile", filebase, makeBenchString(name))
+func makePProfFilename(filebase, name, typ string) string {
+	return fmt.Sprintf("%s_%s.%s", filebase, makeBenchString(name), typ)
 }
diff --git a/src/cmd/link/internal/benchmark/bench_test.go b/src/cmd/link/internal/benchmark/bench_test.go
index 48d4d74046..d8ec717c7c 100644
--- a/src/cmd/link/internal/benchmark/bench_test.go
+++ b/src/cmd/link/internal/benchmark/bench_test.go
@@ -39,8 +39,8 @@ func TestPProfFlag(t *testing.T) {
 }
 
 func TestPProfNames(t *testing.T) {
-	want := "foo_BenchmarkTest.profile"
-	if v := makePProfFilename("foo", "test"); v != want {
+	want := "foo_BenchmarkTest.cpuprof"
+	if v := makePProfFilename("foo", "test", "cpuprof"); v != want {
 		t.Errorf("makePProfFilename() == %q, want %q", v, want)
 	}
 }