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| author | Shenghou Ma <minux@golang.org> | 2015-04-23 02:43:10 -0400 |
|---|---|---|
| committer | Minux Ma <minux@golang.org> | 2015-05-01 07:25:49 +0000 |
| commit | 5f69e739d3b01e657e27547641e8db74d2c2a862 (patch) | |
| tree | 4bb111ddb126e987e1c967b8d56cca02a0a1f2fc /src/runtime/trace.go | |
| parent | ffd334493c69bb39bf12ec639f33f8718bff998b (diff) | |
| download | go-5f69e739d3b01e657e27547641e8db74d2c2a862.tar.xz | |
runtime: adjust traceTickDiv for non-x86 architectures
Fixes #10554.
Fixes #10623.
Change-Id: I90fbaa34e3d55c8758178f8d2e7fa41ff1194a1b
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/9247
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
Diffstat (limited to 'src/runtime/trace.go')
| -rw-r--r-- | src/runtime/trace.go | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/src/runtime/trace.go b/src/runtime/trace.go index e0eb7d82ce..3b7501b9b4 100644 --- a/src/runtime/trace.go +++ b/src/runtime/trace.go @@ -60,8 +60,13 @@ const ( // Timestamps in trace are cputicks/traceTickDiv. // This makes absolute values of timestamp diffs smaller, // and so they are encoded in less number of bytes. - // 64 is somewhat arbitrary (one tick is ~20ns on a 3GHz machine). - traceTickDiv = 64 + // 64 on x86 is somewhat arbitrary (one tick is ~20ns on a 3GHz machine). + // The suggested increment frequency for PowerPC's time base register is + // 512 MHz according to Power ISA v2.07 section 6.2, so we use 16 on ppc64 + // and ppc64le. + // Tracing won't work reliably for architectures where cputicks is emulated + // by nanotime, so the value doesn't matter for those architectures. + traceTickDiv = 16 + 48*(goarch_386|goarch_amd64|goarch_amd64p32) // Maximum number of PCs in a single stack trace. // Since events contain only stack id rather than whole stack trace, // we can allow quite large values here. |