Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 24 Jan 2011 18:38:02 -0200 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [GIT PULL] perf fixes |
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Em Tue, Jan 25, 2011 at 06:27:31AM +1000, Linus Torvalds escreveu: > On Tue, Jan 25, 2011 at 6:17 AM, Linus Torvalds > <torvalds@linux-foundation.org> wrote: > > > > It only happens for me with "g". With "perf record -af sleep 10" it worked. > > Actually, it's something subtler than that. It must depend on the > actual data, because now when I tried it again, it worked with 'g' > too. I hadn't saved the old perf.data that caused the lockup (it got > overwritten by the non-g test), and now when I try to re-create it it > doesn't hang on the result. > > So it's probably some very specific data pattern that causes it. > > (And I don't know if it's a hard hang - it could just be something > _very_ slow. But we're talking half a minute kind of slow).
Was this on a freshly installed machine? Or on a freshly updated one?
Probably its the build-id collecting at the end of a session, on the first run you had a cold cache and it had to figure out which binaries to cache on ~/.debug, second time it was already cached so it was fast.
So one way to try to reproduce would be to:
rm -rf ~/.debug
and then try it again.
To double check, you can try to disable the build-id cache with:
--no-buildid-cache or -N
i.e.:
perf record -afN sleep 10
- Arnaldo
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