On 06/29, Peter Zijlstra wrote: > > On Mon, Jun 29, 2015 at 06:02:51AM +0200, Oleg Nesterov wrote: > > > If we change stop_two_cpus() to use stop_work_alloc_one() it can use > > cpu_online(), > > So the one user of this actually needs cpu_active(); we do not want to > go move tasks to an inactive cpu. > > So if you change this to cpu_online() we need to audit the user is doing > the stricter test.
Hmm. But the user (migrate_swap_stop) should check cpu_active() anyway? The cpu_active() checks in stop_two_cpus() can only help to ensure that multi_cpu_stop() won't hang. CPU_DOWN_PREPARE can deactivate either CPU right after the check? Or stop_two_cpus() needs get_online_cpus(). Or I missed something. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
