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Date: Thu, 3 Oct 2013 08:25:05 +0200
From: Ingo Molnar <mingo@kernel.org>
To: Ramkumar Ramachandra <artagnon@gmail.com>
Cc: David Ahern <dsahern@gmail.com>, LKML <linux-kernel@vger.kernel.org>,
        Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Subject: Re: [QUERY] Why does perf-trace need me to be root?
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* Ramkumar Ramachandra <artagnon@gmail.com> wrote:

> David Ahern wrote:
> > If you trust your users make the debugfs mount point rx by group,world.
> 
> Thanks David. I can preserve this configuration across reboots by
> putting an entry in fstab, right? How do I preserve the value of
> /proc/sys/kernel/perf_event_paranoid across reboots?

via:

   echo 'kernel.perf_event_paranoid = -1' >> /etc/sysctl.conf

I think 'perf trace' should probably print such suggestions when it 
notices a privilege problem, to make it far more obvious for new users to 
correctly configure their system for easy tracing.

The current output:

  comet:~/tip> perf trace
  Couldn't read the raw_syscalls tracepoints information!

is as hostile to the user as it gets ;-)

Thanks,

	Ingo