Re: [RFC patch] Use IPI_shortcut for lapic timer broadcast

From: Ingo Molnar
Date: Mon Jun 29 2009 - 05:15:57 EST



* Luming Yu <luming.yu@xxxxxxxxx> wrote:

> Please note this is deep-C-state related. C state does add extra
> latency.. but I don't know how much...

ok, so if each of the CPUs has to be brought out of deep-C and with
each one 50-100 usecs a pop one could see the total time taking more
than 1000 usecs. That would explain the hang.

Ingo
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