Messages in this thread | | | Date | Wed, 05 Nov 2003 13:53:57 +1100 | From | Nick Piggin <> | Subject | Re: get_cycles() on i386 |
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Linus Torvalds wrote:
>On 4 Nov 2003, john stultz wrote: > >>CONFIG_X86_TSC be the devil. Personally, I'd much prefer dropping the >>compile time option and using dynamic detection. Something like (not >>recently tested and i believe against 2.5.something, but you get the >>idea): >> > >Some of the users are really timing-critical (eg scheduler). >
The scheduler uses its own sched_clock which only gives jiffies resolution if CONFIG_NUMA is defined. Unfortunate because I think its interactive behaviour isn't so good with ms resolution.
The scheduler does not need to have synchronised TSCs though, I think. It just means 2 more calls to sched_clock in a slow path (smp migration).
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