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| author | Josh Bleecher Snyder <josharian@gmail.com> | 2018-04-06 17:44:26 -0700 |
|---|---|---|
| committer | Josh Bleecher Snyder <josharian@gmail.com> | 2018-05-01 13:33:01 +0000 |
| commit | dda4591c8cc0b57e76339f1f18a6f5670cee2aaa (patch) | |
| tree | 83366e7467ffafaf9a33f233f7f280b48c37d707 | |
| parent | 9ecf899b295c3661bb6ad0e7345fb479986d13f0 (diff) | |
| download | go-dda4591c8cc0b57e76339f1f18a6f5670cee2aaa.tar.xz | |
runtime: add BenchmarkScanStack
There are many possible stack scanning benchmarks,
but this one is at least a start.
cpuprofiling shows about 75% of CPU in func scanstack.
Change-Id: I906b0493966f2165c1920636c4e057d16d6447e0
Reviewed-on: https://go-review.googlesource.com/105535
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
| -rw-r--r-- | src/runtime/gc_test.go | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/src/runtime/gc_test.go b/src/runtime/gc_test.go index d683d89fe4..4895a0e2ac 100644 --- a/src/runtime/gc_test.go +++ b/src/runtime/gc_test.go @@ -10,6 +10,7 @@ import ( "reflect" "runtime" "runtime/debug" + "sync" "sync/atomic" "testing" "time" @@ -643,3 +644,34 @@ func BenchmarkBulkWriteBarrier(b *testing.B) { runtime.KeepAlive(ptrs) } + +func BenchmarkScanStackNoLocals(b *testing.B) { + var ready sync.WaitGroup + teardown := make(chan bool) + for j := 0; j < 10; j++ { + ready.Add(1) + go func() { + x := 100000 + countpwg(&x, &ready, teardown) + }() + } + ready.Wait() + b.ResetTimer() + for i := 0; i < b.N; i++ { + b.StartTimer() + runtime.GC() + runtime.GC() + b.StopTimer() + } + close(teardown) +} + +func countpwg(n *int, ready *sync.WaitGroup, teardown chan bool) { + if *n == 0 { + ready.Done() + <-teardown + return + } + *n-- + countpwg(n, ready, teardown) +} |