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| author | Brad Fitzpatrick <bradfitz@golang.org> | 2020-06-03 11:03:22 -0700 |
|---|---|---|
| committer | Brad Fitzpatrick <bradfitz@golang.org> | 2020-11-05 16:43:34 +0000 |
| commit | 40f0359d52e04ed124a8f81e1ef8ac86957dd983 (patch) | |
| tree | c54fe0b9d624f5e32660c99d6c3e4b96e966c0ed /src/runtime/malloc.go | |
| parent | db8142fb8631df3ee56983cbc13db997c16f2f6f (diff) | |
| download | go-40f0359d52e04ed124a8f81e1ef8ac86957dd983.tar.gz go-40f0359d52e04ed124a8f81e1ef8ac86957dd983.zip | |
runtime: avoid a bit of unneeded work when MemProfileRate==1
Change-Id: I1dc355bcaeb0e5fb06a7fddc4cf5db596d22e0b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/236148
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Reviewed-by: Austin Clements <austin@google.com>
Diffstat (limited to 'src/runtime/malloc.go')
| -rw-r--r-- | src/runtime/malloc.go | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go index 551acd0796..f20ded5bf7 100644 --- a/src/runtime/malloc.go +++ b/src/runtime/malloc.go @@ -1221,6 +1221,13 @@ func profilealloc(mp *m, x unsafe.Pointer, size uintptr) { // distribution (exp(MemProfileRate)), so the best return value is a random // number taken from an exponential distribution whose mean is MemProfileRate. func nextSample() uintptr { + if MemProfileRate == 1 { + // Callers assign our return value to + // mcache.next_sample, but next_sample is not used + // when the rate is 1. So avoid the math below and + // just return something. + return 0 + } if GOOS == "plan9" { // Plan 9 doesn't support floating point in note handler. if g := getg(); g == g.m.gsignal { |