Re: Perf events warning..

From: Linus Torvalds
Date: Tue May 15 2012 - 11:48:58 EST


On Tue, May 15, 2012 at 3:49 AM, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:
>>
>> It did use "make -j64 test" to make the load a *bit* more interesting
>> (and go noticeably faster), but other than that you got it.
>
> OK, that limits the scope of crazy scenarios I have to consider, still
> no immediate clue though..

Actually, looking into my history, some of them had "-fg", and some of
them used "cycles:p". It looks like I had three different combinations
I used:

- the one I already mentioned:

perf record -f -e cycles:pp make -j64 test

- two variations of the above:

perf record -fg -e cycles:p make -j64 test
perf record -fg -e cycles:pp make -j64 test

and I don't know which of these caused the warning.

I did profile some other things too (I commonly do profiles of "git
diff" and "make -j" on a fully built kernel), but they used the same
flags, so from a perf standpoint they shouldn't be all that different.

Linus
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