Messages in this thread | | | Date | Wed, 29 Mar 2006 19:24:53 -0800 | From | Andrew Morton <> | Subject | Re: [rfc] fix Kconfig, hotplug_cpu is needed for swsusp |
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Ashok Raj <ashok.raj@intel.com> wrote: > > On Wed, Mar 29, 2006 at 02:47:46PM -0800, Andrew Morton wrote: > > Pavel Machek <pavel@ucw.cz> wrote: > > > > > > HOTPLUG_CPU is needed on normal PCs, too -- it is neccessary for > > > software suspend. > > > > > > > OK, this will get ugly. APICs are involved. > > I guess you need only on systems that support >1 cpu right? I doubt you will need > it on a system that cannot run with the config-generic-arch on. although we use bigsmp > when hotplug is turned on, all we really end up is using flat physical mode instead > of using logical mode. > > I still havent understood why this wont work. Choosing CONFIG_X86_GENERICARCH shouldnt > break anything AFAICT. > > Pavel, you could use CONFIG_HOTPLUG_CPU, just need to enable X86_GENERICARCH now. > Is there a reason you think that wont work? I wish we would revert it for a strong > reason that we know will not make hotplug work on certain systems because of this choise > not that we currently have X86_PC now, and are unwiling to change the config. > > (PS: the word bigsmp although sounds like some large NR_CPUS, its just using a mode that > permits the system to work from 1 .. >8 cpus. So there is really nothing determental > to selecting this.)
Something which remains to be beaten into my head: *why* does HOTPLUG_CPU require flat pyhsical mode? What necessitated that change, and cannot we make it work OK in logical mode as well as flat mode? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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