Re: [PATCH] tools, perf: Allow the user to disable time stamps

[Andi Kleen]

Stephane Eranian <eranian@xxxxxxxxxx> writes:
>>
> But getting the mmaps at the right moment is crucial for some apps
> especially if address space is recycled otherwise symbolization
> may be incorrect.

Yes that is why it is only an option and not default.
You need to know what you're doing.

BTW I think the recycle case is not very likely on non JIT.

>> 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?

When I measure a long running process and I know it doesn't
fork/dlopen/jit. Using --initial-delay also helps to skip
the startup phase or attaching later.

I believe it's actually a good choice for most non
forky workloads. But yes it cannot be made default.

-Andi

-- 
ak@xxxxxxxxxxxxxxx -- Speaking for myself only
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