Messages in this thread | | | Date | Tue, 27 Aug 2013 07:58:12 -0600 | From | David Ahern <> | Subject | Re: suspicious RCU usage (perf) |
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On 8/27/13 7:10 AM, Steven Rostedt wrote: > On Mon, 26 Aug 2013 15:49:24 -0400 > Dave Jones <davej@redhat.com> wrote: > > >> > Do you have /sys/kernel/debug with access permissions? >> >> Ah, yeah, that'll be it. Good catch. >> >> Sorry for the false alarm Steve ;) > > Yeah, but it still does not explain how perf got started. Perf requires > a sys_perf_event_open() call to run.
Per Peter's response another option is the paranoia level:
# perf event paranoia level: # -1 - not paranoid at all # 0 - disallow raw tracepoint access for unpriv # 1 - disallow cpu events for unpriv # 2 - disallow kernel profiling for unpriv kernel.perf_event_paranoid = -1
I keep my dev box at -1 and set /sys/kernel/debug to 755 to run perf as non-root.
David
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