Re: [patch] genapic: optimize & fix APIC mode setup

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



* Siddha, Suresh B <[email protected]> wrote:

> On Mon, Nov 13, 2006 at 07:42:56PM +0100, Ingo Molnar wrote:
> > * Siddha, Suresh B <[email protected]> wrote:
> > > Not really. That chipset belongs to a MP platform and with your 
> > > proposed patch, we will endup using clustered APIC mode and will hit 
> > > the issue(in the presence of cpu hotplug) mentioned in that URL.
> > 
> > hm, why does it end up in clustered mode? Cluster mode should only 
> > trigger if the APIC IDs go beyond 16.
> 
> go beyond '8' not 16. With Dual-core+HT these MP platforms will have 
> 16 logical cpus.

yes - then the APIC ids will go beyond 15.

> > but i'd be fine with never going into cluster mode, instead always 
> > using physical flat mode when having more than 8 APICs (independent 
> > of the presence of CPU hotplug). On small systems, logical flat mode 
> > is what is the best-tested variant (it's also slightly faster).
> 
> Ok.

ok, that's really good. Is there any 'weird' platform that you are aware 
of that absolutely needs clustered APIC mode (because it has no physical 
delivery mode or something)?

	Ingo
-
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/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux