Messages in this thread | | | Date | Wed, 8 Nov 2017 12:56:43 -0800 | From | Andi Kleen <> | Subject | Re: [PATCH v3 4/5] perf/record: add documentation for sampling skid ip |
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> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt > index 5a626ef666c2..3b156fa03c99 100644 > --- a/tools/perf/Documentation/perf-record.txt > +++ b/tools/perf/Documentation/perf-record.txt > @@ -57,6 +57,14 @@ OPTIONS > FP mode, "dwarf" for DWARF mode, "lbr" for LBR mode and > "no" for disable callgraph. > - 'stack-size': user stack size for dwarf mode > + - 'skid_ip' : boolean, captures the unmodified interrupt instruction pointer > + (IP) in each sample. Usually with event-based sampling, the IP > + has skid and rarely point to the instruction which caused the > + event to overflow. On some architectures, the hardware can eliminate > + the skid and perf_events returns it as the IP with precise sampling is > + enabled. But for certain measurements, it may be useful to have both > + the correct and skid ip. This option enable capturing the skid ip in > + additional to the corrected ip. Default is: false
Actually in the scanner you use 'skid-ip' (with minus). Documentation should at least match the scanner.
_ is usually safer than -
-Andi
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