Re: perf_evlist__filter_pollfd() in trace__run()

From: Arnaldo Carvalho de Melo
Date: Sun Feb 01 2015 - 09:10:30 EST


Em Fri, Jan 30, 2015 at 12:16:11PM -0800, Sukadev Bhattiprolu escreveu:
> Arnaldo Carvalho de Melo [acme@xxxxxxxxxx] wrote:
> | Em Thu, Jan 29, 2015 at 03:55:22PM -0800, Sukadev Bhattiprolu escreveu:
> | > Should there be another check to before reading the mmap again ?
> |
> | Possibly, checking, but a similar algorithm should be in place for
> | 'record', do you see any problems there? I.e. with 'perf record sleep
> | 1'?
>
> No, I don't see the failure with perf record in several hundred attempts.
> (both the distro and latest perf-core versions work ok).

Ok, so its a matter of comparing what both are doing, will try.

> | > I must add that I don't get the SIGSEGV on recent perf-core and the
> | > system where we get the crash, first runs into the following
> | > errors that we are still looking into (maybe related to "ppc64le"
> | > architecture).
>
> With recent perf core I did not get the SIGSEGV (or the syscall translation
> failures below) on a different system.
>
> But on this system, a power KVM guest, I get both errors even with latest
> perf core (commit c52686f9f88).
>
> | >
> | > Problems reading syscall 45 information
> | > Problems reading syscall 5 information
> | > Problems reading syscall 5 information
> | > Problems reading syscall 108 information
> | > Problems reading syscall 108 information
> | > Problems reading syscall 90 information
> | > Problems reading syscall 90 information
> | > Problems reading syscall 6 information
> | >
> | > Unlike the SIGSEGV, these errors occur always.
>
> Most likely this syscall number translation is due to the
>
> https://fedorahosted.org/audit/browser/trunk/lib/machinetab.h
>
> missing this change set 1013, which added support for ppc64le.

We have to improve that message to mention that perhaps a newer
audit-libs package is required.

- Arnaldo
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