Messages in this thread | | | Subject | Re: [PATCH 1/2] perf: Add persistent events | From | Peter Zijlstra <> | Date | Sun, 23 May 2010 21:23:21 +0200 |
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On Sun, 2010-05-23 at 20:54 +0200, Borislav Petkov wrote: > From: Peter Zijlstra <peterz@infradead.org> > Date: Sun, May 23, 2010 at 08:40:47PM +0200 > > > > > A persistent event would simply be a regular event, but created by the > > > > kernel and not tied to a file-desc's lifetime. > > > > > > So you're saying the trace_mce_record() tracepoint for example should > > > be created completely internally in the kernel and cease to be a > > > tracepoint? Will it still be able to be selected by perf -e? > > > > No, it should be a regular tracepoint as far as tracepoints are > > concerned. > > > > But the only thing persistence should add is an instance of a > > perf_event, it should not modify either the perf_event nor the > > tracepoint code. > > which means that subsystems which initialize earlier than perf (mce, > for example) should have to be notified when perf is ready so that they > could register a persistent event. How does that sound?
Either we add some notifier thing, or we simply add an explicit call in the init sequence after the perf_event subsystem is running. I would suggest we start with some explicit call, and take it from there.
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