On 12/21/2011 10:40 AM, Colin Cross wrote: >> this smells fundamentally racey to me; you can get an interrupt one >> cycle after you think you're done, but before the last guy enters WFI... >> >> how do you solve that issue ? > > All the cpus have interrupts off when they increment the counter, so > they cannot receive an interrupt. If an interrupt is pending on one > of those cpus, it will be handled later when WFI aborts due to the > pending interrupt. ... but this leads to cases where you're aborting before other cpus are entering..... so your "last guy in" doesn't really work, since while cpu 0 thinks it's the last guy, cpu 1 is already on the way out/out already... (heck it might already be going back to sleep if your idle code can run fast, like in the size of a cache miss) _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/linux-pm
