Messages in this thread | | | Date | Fri, 12 Apr 2013 10:56:35 -0700 | From | Arjan van de Ven <> | Subject | Re: [PATCH documentation 1/2] nohz1: Add documentation. |
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> ------------------------------------------------------------------------ > > 1. It increases the number of instructions executed on the path > to and from the idle loop. > > 2. On many architectures, dyntick-idle mode also increases the > number of times that clocks must be reprogrammed, and this > reprogramming can be quite expensive.
it's really that we're no longer using periodic clocks, but only one-shot clocks only. (which then leads to having to program them every time)
but arguably, that's because of HRTIMERS more than NOHZ (e.g. I bet we still turn off periodic even for nohz as long as hrtimers are enabled)
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