Messages in this thread | | | Date | Tue, 31 Jan 2012 05:41:55 -0800 | From | Arjan van de Ven <> | Subject | Re: smp: Start up non-boot CPUs asynchronously |
| |
On Tue, 31 Jan 2012 13:52:32 +0100 Ingo Molnar <mingo@elte.hu> wrote: > > The real fix would be to make the init code depend less on each > other, i.e. have less hotplug lock dependencies. Or, if it's > such a hot lock for a good reason, why does spinning on it slow > down the boot process? It really shouldnt.
by inspection, anything that calls get_online_cpus()/put_online_cpus() will block while a CPU is coming up. This is used in things like kmem_cache_create()... which is used about everywhere. (there's various other places... more or less it's a requirement for using the for_each_online_cpu() api correctly)
-- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org
| |