Messages in this thread | | | Date | Tue, 25 Mar 2014 23:15:05 +0100 | Subject | Re: [PATCH] tools, perf: Allow the user to disable time stamps | From | Stephane Eranian <> |
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On Tue, Mar 25, 2014 at 10:01 PM, Andi Kleen <ak@linux.intel.com> wrote: >> >> Timestamp are useful to order samples during reporting. >> How do you do with it if you monitor multi-threaded (multi-cpu) >> workloads. This is only good for single thread or single CPU >> measurements. Or am I missing something? > > For a perf report order doesn't matter (except against mmaps) > The CPUs are still separated of course > But getting the mmaps at the right moment is crucial for some apps especially if address space is recycled otherwise symbolization may be incorrect.
> You're right for some special analysis it matters, that is why > it is only an option. > > But for the standard "only care about perf report and > don't care about about program startup" case it's a nice saving. > How do you know in advance you won't need mmap ordering?
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