Messages in this thread | | | Date | Thu, 19 Aug 2004 09:49:46 +0200 | From | Ingo Molnar <> | Subject | Re: [patch] voluntary-preempt-2.6.8.1-P2 |
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* Thomas Charbonnel <thomas@undata.org> wrote:
> When entering check_preempt_timing, preempt_thresh was 0, and > preempt_max_latency had been freshly reset to 100. It should have > triggered this code : > > if (latency < preempt_max_latency) > goto out; > > but for some reason it didn't (or there is a problem in the tracing > code, not showing events that would have increased 'latency').
there is one case where we could 'miss' a new latency: when /proc/latency_trace is accessed. For the duration of /proc/latency_trace access, the updating of the max latency is stopped:
if (down_trylock(&max_mutex)) goto out;
this is not really a practical problem and fixing it would be quite complex.
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