On Fri, 9 Sep 2005, Andrew Morton wrote:
> > static void __init MP_processor_info (struct mpc_config_processor *m)
> > {
> > - int ver, apicid;
> > + int ver, apicid, cpu, found_bsp = 0;
> > physid_mask_t tmp;
> >
> > if (!(m->mpc_cpuflag & CPU_ENABLED))
> > @@ -181,6 +181,7 @@ static void __init MP_processor_info (st
> > if (m->mpc_cpuflag & CPU_BOOTPROCESSOR) {
> > Dprintk(" Bootup CPU\n");
> > boot_cpu_physical_apicid = m->mpc_apicid;
> > + found_bsp = 1;
> > }
> >
> > if (num_processors >= NR_CPUS) {
> > @@ -204,6 +205,11 @@ static void __init MP_processor_info (st
> > return;
> > }
> >
> > + if (found_bsp)
> > + cpu = 0;
> > + else
> > + cpu = num_processors - 1;
> > + cpu_set(cpu, cpu_possible_map);
>
> Looky here:
>
> akpm: found_bsp=0 cpu=0 tmp=0x0001 num_processors=1
> akpm: found_bsp=0 cpu=1 tmp=0x0002 num_processors=2
> akpm: found_bsp=0 cpu=2 tmp=0x0004 num_processors=3
> akpm: found_bsp=1 cpu=0 tmp=0x0008 num_processors=4
>
> On this machine, the BSP is the last one to pass through
> MP_processor_info(), so the rude-looking assumption above screws things up.
Yes that's a terrible assumption,
> I don't know what that found_bsp code is trying to do. It wasn't
> changelogged and it wasn't commented and removing it makes by box boot again.
>
> What did I break?
Nothing gov =)
> - if (found_bsp)
> - cpu = 0;
> - else
> - cpu = num_processors - 1;
> - cpu_set(cpu, cpu_possible_map);
> - tmp = apicid_to_cpu_present(apicid);
> - physids_or(phys_cpu_present_map, phys_cpu_present_map, tmp);
> -
> + cpu_set(num_processors, cpu_possible_map);
> + num_processors++;
> + phys_cpu = apicid_to_cpu_present(apicid);
> + physids_or(phys_cpu_present_map, phys_cpu_present_map, phys_cpu);
> +
That looks fine to me, my BSP assumption was bad bad bad!
Thanks,
Zwane
-
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/
