Re: [GIT PULL 00/16] perf/core improvements and fixes

[Namhyung Kim]

2012-02-14 12:07 PM, Namhyung Kim wrote:
> 2012-02-14 ìì 11:50, Namhyung Kim ì ê:
> > Hello,
> >
> > 2012-02-14 10:52 AM, Arnaldo Carvalho de Melo wrote:
> > > The following changes since commit c98fdeaa92731308ed80386261fa2589addefa47:
> > >
> > > x86/sched/perf/AMD: Set sched_clock_stable (2012-02-07 13:12:08 +0100)
> > >
> > > are available in the git repository at:
> > >
> > > git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux perf-core-for-mingo
> > >
> > > for you to fetch changes up to 7e1ccd3804281fc0755eb726b654469c40a96d89:
> > >
> > > perf tools: cleanup initialization of attr->size (2012-02-13 23:35:04 -0200)
> > >
> > > ----------------------------------------------------------------
> > > perf/core fixes and improvements.
> > >
> > > Signed-off-by: Arnaldo Carvalho de Melo<acme@xxxxxxxxxx>
> >
> > I've got a following error during a simple test:
> >
> > $ ./perf record -- sleep 1
> >
> > Error: sys_perf_event_open() syscall returned with 22 (Invalid argument).
> > /bin/dmesg may provide additional information.
> >
> > Fatal: No CONFIG_PERF_EVENTS=y kernel support configured?
> >
> > sleep: Terminated
> >
> >
> > Any thoughts?
> >
> > Thanks,
> > Namhyung
>
> git bisect told me:
>
> c4a7dca92bbb9881a5d678720f1d0c2153499749 is the first bad commit
> commit c4a7dca92bbb9881a5d678720f1d0c2153499749
> Author: Joerg Roedel<joerg.roedel@xxxxxxx>
> Date:   Fri Feb 10 18:05:05 2012 +0100
>
>      perf tools: Change perf_guest default back to false
>
>      Setting perf_guest to true by default makes no sense because the perf
>      subcommands can not setup guest symbol information and thus not process
>      and guest samples. The only exception is perf-kvm which changes the
>      perf_guest value on its own.  So change the default for perf_guest back
>      to false.
>
>      Cc: David Ahern<dsahern@xxxxxxxxx>
>      Cc: Ingo Molnar<mingo@xxxxxxx>
>      Cc: Jason Wang<jasowang@xxxxxxxxxx>
>      Cc: Paul Mackerras<paulus@xxxxxxxxx>
>      Cc: Peter Zijlstra<a.p.zijlstra@xxxxxxxxx>
>      Link: http://lkml.kernel.org/r/1328893505-4115-3-git-send-email-joerg.roedel@xxxxxxx
>      Signed-off-by: Joerg Roedel<joerg.roedel@xxxxxxx>
>      Signed-off-by: Arnaldo Carvalho de Melo<acme@xxxxxxxxxx>
>
> :040000 040000 64d65944c9081dfd9ace65dbc19fca655cbdc708 4f0e86ab85314ba68f2295ae1e599f3bb5ab9484 M      tools
>
>
> Thanks,
> Namhyung

It happened because I used old kernel version that isn't aware of the 
exclude_guest bit. So the check on attr->__reserved_1 in 
core.c::perf_copy_attr() failed and then ended up seeing EINVAL at 
perf_evsel__open().

So I think it should be handled in the same way of handling sample_id_all bit 
in perf record and top if we want to set perf_guest to false by default. I'll 
send patches for them soon.

Thanks,
Namhyung
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