Messages in this thread | | | Date | Mon, 10 Nov 2014 13:29:54 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH V3 1/6] sched: idle: Add a weak arch_cpu_idle_poll function |
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On Fri, Nov 07, 2014 at 03:31:22PM +0100, Daniel Lezcano wrote: > The poll function is called when a timer expired or if we force to poll when > the cpu_idle_force_poll option is set. > > The poll function does: > > local_irq_enable(); > while (!tif_need_resched()) > cpu_relax(); > > This default poll function suits for the x86 arch because its rep; nop; > hardware power optimization. But on other archs, this optimization does not > exists and we are not saving power. The arch specific bits may want to > optimize this loop by adding their own optimization.
This doesn't make sense to me; should an arch not either implement an actual idle driver or implement cpu_relax() properly, why allow for a third weird option?
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