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Re: hyperthreading and tstile



Le 19/10/2013 20:28, Patrick Welche a écrit :
Could the tstiles have been because of the cpu which failed to become
ready?

I don't think so, CPUs that failed to init cannot take part in the scheduling.

However, if another cpu starts acting in the same way (ie. fails to wake up after being signaled), LWPs may become blocked in tstile. They are waiting for a ressource that will probably never be available again if the CPU went away.

It would be more useful to see the ressources on which all LWPs are waiting on though.

Is that really a hardware problem?

We have to test it more before saying anything. If you cannot reproduce the same issue with another OS while keeping HT enabled (4 CPUs available and working), NetBSD is missing something. Caching issues probably, HT play dirty tricks with those.

Otherwise, the hardware issue is a good candidate; but I doubt that.

--
Jean-Yves Migeon


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