On Fri, 2012-05-04 at 14:27 -0700, Nishanth Aravamudan wrote: > > - if you retain it for cpuset but not others that's confusing (too); > > That's a good point. > > Related, possibly counter-example, and perhaps I'm wrong about it. When > we hot-unplug a CPU, and a task's scheduler affinity (via > sched_setaffinity) refers to that CPU only, do we kill that task? Can > you sched_setaffinity a task to a CPU that is offline (alone or in a > group of possible CPUs)? Or is it allowed to run anywhere? Do we destroy > its affinity policy when that situation is run across? See a few emails back, we destroy the affinity. Current cpuset behaviour can be said to match that. > Or do we restore the task to the CPU again when we re-plug it? Nope that information is lost forever from the kernels pov. Keeping this information around for the off-chance of needing it is rather expensive (512 bytes per task for your regular distro kernel that has NR_CPUS=4096). -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
