Messages in this thread | | | Date | Mon, 24 Nov 2008 22:18:49 +0200 | From | Pekka Paalanen <> | Subject | Re: [PATCH 1/2] mmiotrace: fix buffer overrun detection |
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On Sun, 23 Nov 2008 20:34:13 +0100 Ingo Molnar <mingo@elte.hu> wrote:
> Sure - applied them to tip/tracing/urgent: > > fb91ee6: tracing, doc: update mmiotrace documentation > 7ee1768: x86, mmiotrace: fix buffer overrun detection > > Does this make mmiotrace fully functional in .28 ?
Oh right, the busylooping bug when echoing into trace_marker, I already forgot about that, since I couldn't reproduce it. I guess there's nothing to do, until someone finds a way to reproduce it.
I could speculate about buffer wrap-around issues or such, but that requires some serious code reviewing. Btw. C-c'ing didn't interrupt the shell while spinning. The spinning ended when I switched the tracer or disabled it, IIRC.
(This is related to 2.6.28-rc6.)
On Sun, 23 Nov 2008, Pekka Paalanen wrote:
> There's also another issue, but I am not sure how to reproduce it. > The symptom is, that > echo whatever > /debug/tracing/trace_marker > gets stuck in a loop, bash eats 100% CPU: 10% user, 90% system. > I got that twice today, like this: after a fresh boot echoing 64, 200, > 70 to trace_entries, switching between nop and mmiotrace tracers, > echoing 0 or 1 to tracing_enabled, and running the testmmiotrace > module. At some point the user marker got stuck. > > But then I tried to do that a third time by repeating some usage > patterns I thought might trigger it, but it didn't happen.
-- Pekka Paalanen http://www.iki.fi/pq/
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