Messages in this thread | | | Date | Wed, 17 May 2006 11:43:32 +1000 | From | Peter Chubb <> | Subject | Re: [RFC] [Patch 7/8] statistics infrastructure - exploitation prerequisite |
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>>>>> "Andi" == Andi Kleen <ak@suse.de> writes:
Anrd> - do_gettimeofday potentially slow, reliable TOD clock, Anrd> microsecond resolution >> Slow, not necessarily safe to call in IRQ context.
Andi> It's only slow if the platform can't do better. On good hardware Andi> it is fast. And yes it is safe to call in IRQ Andi> context. Networking does that all the time.
Thanks for the clarification.
I measured do_gettimeofday on IA64 at around 120 cycles (mind you that was some time ago now, before the last lot of time function revisions in the kernel). Whether that's slow or not depends on your application.
-- Dr Peter Chubb http://www.gelato.unsw.edu.au peterc AT gelato.unsw.edu.au http://www.ertos.nicta.com.au ERTOS within National ICT Australia - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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