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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?
Date: Thu, 3 Oct 2013 08:25:05 +0200	[thread overview]
Message-ID: <20131003062505.GE25345@gmail.com> (raw)
In-Reply-To: <CALkWK0kzXnBKiRyN5HPE-_nScOG-JKjAnD1ujxA_R8tWQWrxZQ@mail.gmail.com>


* 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

  reply	other threads:[~2013-10-03  6:25 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-02  9:20 [QUERY] Why does perf-trace need me to be root? Ramkumar Ramachandra
2013-10-02 13:02 ` David Ahern
2013-10-03  5:06   ` Ramkumar Ramachandra
2013-10-03  6:25     ` Ingo Molnar [this message]
2013-10-03  7:20       ` Ramkumar Ramachandra
2013-10-03  7:34         ` Ingo Molnar
2013-10-03 17:21       ` Arnaldo Carvalho de Melo

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