* Andrew Morton <a...@linux-foundation.org> wrote: > On Wed, 24 Apr 2013 06:18:50 -0500 Robin Holt <h...@sgi.com> wrote: > > > We recently noticed that reboot of a 1024 cpu machine takes approx 16 > > minutes of just stopping the cpus. The slowdown was tracked to commit > > f96972f. > > > > The current implementation does all the work of hot removing the cpus > > before halting the system. We are switching to just migrating to the > > boot cpu and then continuing with shutdown/reboot. > > > > This also has the effect of not breaking x86's command line parameter for > > specifying the reboot cpu. Note, this code was shamelessly copied from > > arch/x86/kernel/reboot.c with bits removed pertaining to the reboot_cpu > > command line parameter. > > > > @@ -357,6 +357,24 @@ int unregister_reboot_notifier(struct notifier_block > > *nb) > > } > > EXPORT_SYMBOL(unregister_reboot_notifier); > > > > +static void migrate_to_reboot_cpu(void) > > +{ > > + /* The boot cpu is always logical cpu 0 */ > > + int reboot_cpu_id = 0; > > + > > + cpu_hotplug_disable(); > > + > > + /* Make certain the cpu I'm about to reboot on is online */ > > + if (!cpu_online(reboot_cpu_id)) > > + reboot_cpu_id = cpumask_first(cpu_online_mask); > > + > > + /* Prevent races with other tasks migrating this task */ > > + current->flags |= PF_THREAD_BOUND; > > PF_THREAD_BOUND was removed/replaced in linux-next's a9ab775bc > ("workqueue: directly restore CPU affinity of workers from CPU_ONLINE")
I don't see PF_THREAD_BOUND being removed by commit a9ab775bc. Did you mean some other commit? Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/