Messages in this thread | | | Date | Sun, 29 Jan 2012 19:50:57 +0200 | From | Gleb Natapov <> | Subject | Re: perf: prctl(PR_TASK_PERF_EVENTS_DISABLE) has no effect |
| |
On Sun, Jan 29, 2012 at 05:32:35PM +0100, Ingo Molnar wrote: > > * Andrew Steets <asteets@rgmadvisors.com> wrote: > > > On 1/28/12 6:01 AM, Ingo Molnar wrote: > > > > >> prctl(PR_TASK_PERF_EVENTS_DISABLE) doesn't appear to > > >> disable perf event counters. Here is a demonstration > > >> program: > > > > > > btw., what's your usecase? > > > > I'm trying to profile a small section of a long-running > > program. I ran into trouble using call-graph recording and I > > thought this might be an alternative way of getting what I was > > after. > > That usecase indeed makes sense. Peter, could we allow this for > privileged tasks, depending on the perf_paranoia settings or > such? > This sounds useful not only for privileged tasks. Why not make it event attribute? If user wants PR_TASK_PERF_EVENTS_DISABLE be respected for an event it can specify special argument like:
perf record -e cycles:n ./a.out
-- Gleb.
| |