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| author | Andy Pan <panjf2000@gmail.com> | 2020-11-10 21:02:18 +0800 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2021-02-23 16:02:56 +0000 |
| commit | 55d7dcc3cd4b3ee6bca0ab7101866d785776ff51 (patch) | |
| tree | 6fea51642a39340177a807e87324a3b5e6603c04 /src/runtime/runtime2.go | |
| parent | ab331c0254d4462dde6640ec9b00fecc828f4162 (diff) | |
| download | go-55d7dcc3cd4b3ee6bca0ab7101866d785776ff51.tar.gz go-55d7dcc3cd4b3ee6bca0ab7101866d785776ff51.zip | |
runtime: optimize the memory padding in p struct
Since allocation for p struct will be rounded up to the next size class,
the two relevant adjacent classes for this case are 9728 bytes and 10240 bytes.
A p is currently 10072 bytes, so it gets rounded up to 10240 bytes when we allocate one,
So the pad in p struct is unnecessary, eliminate it and add comments for
warning the false sharing.
Change-Id: Iae8b32931d1beddbfff1f58044d8401703da6407
Reviewed-on: https://go-review.googlesource.com/c/go/+/268759
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Ian Lance Taylor <iant@golang.org>
Diffstat (limited to 'src/runtime/runtime2.go')
| -rw-r--r-- | src/runtime/runtime2.go | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go index 5bd283d12f..f5318e6f11 100644 --- a/src/runtime/runtime2.go +++ b/src/runtime/runtime2.go @@ -5,7 +5,6 @@ package runtime import ( - "internal/cpu" "runtime/internal/atomic" "runtime/internal/sys" "unsafe" @@ -713,7 +712,8 @@ type p struct { // scheduler ASAP (regardless of what G is running on it). preempt bool - pad cpu.CacheLinePad + // Padding is no longer needed. False sharing is now not a worry because p is large enough + // that its size class is an integer multiple of the cache line size (for any of our architectures). } type schedt struct { |