linux-kernel - Re: BUG: perf top enters loop synthesizing events for existing threads

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Message-ID: <552531A7.9070605@gmail.com>
Date:	Wed, 08 Apr 2015 07:48:23 -0600
From:	David Ahern <dsahern@...il.com>
To:	Arnaldo Carvalho de Melo <arnaldo.melo@...il.com>
CC:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Don Zickus <dzickus@...hat.com>, Jiri Olsa <jolsa@...nel.org>,
	Joe Mario <jmario@...hat.com>, Ingo Molnar <mingo@...nel.org>
Subject: Re: BUG: perf top enters loop synthesizing events for existing threads

On 4/8/15 7:45 AM, Arnaldo Carvalho de Melo wrote:
>> I also noticed that if I set /proc/sys/kernel/perf_event_paranoid to -1
>> to run it as !root, then the problem "goes away", which I think probably
>> is explained by, as !root, not being able to parse some of the /proc
>> files for existing threads and thus not triggering the bug, still
>> investigating...

odd. because this has nothing to do with perf_events; it is just walking 
/proc and for the ppid adds a strstr and atoi(str). Something else is at 
play. I'll take a look.

David
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