Messages in this thread | | | Date | Wed, 24 Apr 2002 13:20:48 -0700 | From | george anzinger <> | Subject | Re: Why HZ on i386 is 100 ? |
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Alan Cox wrote: > > > I must not be making my self clear :) The overhead has nothing to do > > with hardware. It is all timer list insertion and deletion. The > > problem is that we need to do this at context switch rates, which are > > MUCH higher that tick rates and, even with the O(1) insertion code, > > cause the overhead to increase above the ticked overhead. > > I remain unconvinced. Firstly the timer changes do not have to > occur at schedule rate unless your implementaiton is incredibly naiive.
OK, I'll bite, how do you stop a task at the end of its slice if you don't set up a timer event for that time?
> Secondly for the specfic schedule case done that way, it would be even more > naiive to use the standard timer api over a single compare to getthe > timer list versus schedule clock.
I guess it is my day to be naive :) What are you suggesting here?
-- George Anzinger george@mvista.com High-res-timers: http://sourceforge.net/projects/high-res-timers/ Real time sched: http://sourceforge.net/projects/rtsched/ Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml - 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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