Messages in this thread | | | Date | Thu, 15 Jan 2009 06:04:55 -0800 | From | Mandeep Singh Baines <> | Subject | Re: [PATCH] softlockup: detect bottom-half lockups |
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Stumbled upon ftrace tracepoints while writing this patch. Should make life a lot easier for debugging latency issues.
bhlockup should complement ftrace. Once you've found that there's a problem, tracing can be a big help in debugging. But assertions are nice for finding problems you didn't know exist.
Ingo Molnar (mingo@elte.hu) wrote: > > * Mandeep Singh Baines <msb@google.com> wrote: > > > The feature should be useful to real-time developers and developers of > > network and other high-performance drivers. > > hm, did you know about the ftrace latency tracers: > > config IRQSOFF_TRACER > bool "Interrupts-off Latency Tracer" > > config PREEMPT_TRACER > bool "Preemption-off Latency Tracer" > > config SCHED_TRACER > bool "Scheduling Latency Tracer" > > PREEMPT_TRACER would have shown you that softirqs-off section very nicely. > > (And if you also enable the function tracer then not just the latency > endpoint is shown, but also all the function calls that happened in the > critical section.) > > Ingo
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