Messages in this thread | | | Date | Thu, 07 May 2009 14:01:07 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] x86: Reduce the default HZ value |
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Peter Zijlstra wrote: > > The problem with scheduling a hrtimer along with tasks is that at high > context switch rates the timer will never fire but you do pay the > overhead of programming the hardware each time, something that can be > about as expensive as the whole context switch itself. > > Although, I guess we could amortize that by not re-programming the timer > when the existing timer is within a reasonable period (say 1ms) of the > requested on. >
That seems like a reasonable optimization since we're talking about multi-kHz context switch rates, here.
-hpa
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