Re: [patch] Real-Time Preemption, -RT-2.6.10-rc1-mm3-V0.7.23

From: Ingo Molnar
Date: Tue Nov 09 2004 - 17:23:05 EST



* Mark_H_Johnson@xxxxxxxxxxxx <Mark_H_Johnson@xxxxxxxxxxxx> wrote:

> [3] I am not so sure that the latency tracing works. I do not get any
> trace output, even if I set preempt_max_latency to zero.

What is the value of preempt_thresh? If it's set then it overrides the
preempt_max_latency value. (previously the bogus timing values probably
triggered even a relatively high preempt-threshold, but now with a
correct tracer it's not possible anymore.)

> [...] I also noticed that /proc/sys/kernel/preempt_wakeup_timing was
> removed at .20 but not sure if that was deliberate. [...]

yeah, this was deliberate - it's a side-effect of separating it from the
other timing options.

Ingo
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