Re: [Bug #12465] KVM guests stalling on 2.6.28 (bisected)

[Steven Rostedt]

On Tue, 20 Jan 2009, Ingo Molnar wrote:
> Another test would be to build the scheduler latency tracer into your 
> kernel:
> 
>     CONFIG_SCHED_TRACER=y
> 
> And enable it via:
> 
>     echo wakeup > /debug/tracing/current_tracer
> 
> and you should be seeing the worst-case scheduling latency traces in 
> /debug/tracing/trace, and the largest observed latency will be in 
> /debug/tracing/tracing_max_latency [in microseconds].

Note, the wakeup latency only tests realtime threads, since other threads
can have other issues for wakeup. I could change the wakeup tracer as
wakeup_rt, and make a new "wakeup" that tests all threads, but it may
be difficult to get something accurate.

-- Steve
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