On Tue, Nov 28, 2006 at 09:23:22PM +0100, Ingo Molnar wrote: > > * Siddha, Suresh B <[EMAIL PROTECTED]> wrote: > > > On Tue, Nov 28, 2006 at 07:33:46AM +0100, Ingo Molnar wrote: > > > - if (clusters <= 1 && max_cluster <= 8 && cluster_cnt[0] == max_cluster) > > > + if (max_apic < 8) > > > > Patch mostly looks good. Instead of checking for max_apic, can we use > > cpus_weight(cpu_possible_map) <= 8 > > ok - but i think it's still possible the BIOS tells us APIC IDs that are > larger than 7, even if there are fewer CPUs. So i think the patch below > should cover it. Agreed? >
I think it is ok to use flat mode even when APIC IDs are larger than 7, as we rely on LDR's which are programmed using smp_processor_id(). IMO, cpus_weight check should be fine. thanks, suresh > Ingo > > --------------------> > From: Ingo Molnar <[EMAIL PROTECTED]> > Subject: [patch] genapic: default to physical mode on hotplug CPU kernels > > default to physical mode on hotplug CPU kernels. > > Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]> > > Index: linux/arch/x86_64/kernel/genapic.c > =================================================================== > --- linux.orig/arch/x86_64/kernel/genapic.c > +++ linux/arch/x86_64/kernel/genapic.c > @@ -51,7 +51,7 @@ void __init clustered_apic_check(void) > max_apic = id; > } > > - if (max_apic < 8) > + if (max_apic < 8 && cpus_weight(cpu_possible_map) <= 8) > genapic = &apic_flat; > else > genapic = &apic_physflat; - 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/
