>> 2/2 : switching to physical mode APIC setup in case of more than 8 CPU
system
[...]
>> - printk("Enabling APIC mode: ");
>> - if(clustered_apic_mode == CLUSTERED_APIC_NUMAQ)
>> - printk("Clustered Logical. ");
>> - else if(clustered_apic_mode == CLUSTERED_APIC_XAPIC)
>> - printk("Physical. ");
>> - else
>> - printk("Flat. ");
>> - printk("Using %d I/O APICs\n",nr_ioapics);
>IIRC NUMA-Q can be dynamically detected at boot by means of an MP OEM
>table's presence, in particular if there's a matching string in the 8B
>OEM record in the OEM table, with a value of "IBM NUMA" IIRC. This is
>probably a line or two's worth of change to mpparse.c and declaring a
>variable for clustered_apic_mode. If it were difficult to detect, I
>wouldn't have suggested implementing it (though do so at your leisure). =)
The format for the OEM table is pretty much freelance. ES7000 uses it in the
most informal way. However, we need information from this table to switch to
APIC mode, start CPUs, etc. To have the hook for OEM tables in MP parsing
(and in ACPI, for that matter) seems pretty natural. Or if reading of the
OEM table could also be done in more generic way so other platforms had
chance to read their tables seamlessly...
Also, could the clustered_logical and clustered_physical modes be
implemented as a primary item, with NUMA being a secondary with the set of
its unique features on top of the certain APIC mode? This way, a clustered
mode for the APIC could be selectable without NUMA. CLUSTERED_APIC_NUMAQ
could be still an option with an appropriate clustered mode defined.
--Natalie
>I still think this is 2.5 material + backport once it gets testing there.
>Bill
>> IIRC NUMA-Q can be dynamically detected at boot by means of an MP OEM
>> table's presence, in particular if there's a matching string in the 8B
>> OEM record in the OEM table, with a value of "IBM NUMA" IIRC. This is
>> probably a line or two's worth of change to mpparse.c and declaring a
>> variable for clustered_apic_mode. If it were difficult to detect, I
>> wouldn't have suggested implementing it (though do so at your leisure).
>> =)
I don't think you need the OEM table to detect this, current patches do:
+static inline void mps_oem_check(struct mp_config_table *mpc, char *oem,
+ char *productid)
+{
+ if (strncmp(oem, "IBM NUMA", 8))
+ printk("Warning! May not be a NUMA-Q system!\n");
+ if (mpc->mpc_oemptr)
+ smp_read_mpc_oem((struct mp_config_oemtable *)
mpc->mpc_oemptr,
+ mpc->mpc_oemsize);
+}
@@ -376,7 +368,7 @@ static int __init smp_read_mpc(struct mp
str[12]=0;
printk("Product ID: %s ",str);
- summit_check(oem, str);
+ mps_oem_check(mpc, oem, str);
printk("APIC at: 0x%lX\n",mpc->mpc_lapic);
> The format for the OEM table is pretty much freelance. ES7000 uses it in
> the most informal way. However, we need information from this table to
> switch to APIC mode, start CPUs, etc. To have the hook for OEM tables in
> MP parsing (and in ACPI, for that matter) seems pretty natural. Or if
> reading of the OEM table could also be done in more generic way so other
> platforms had chance to read their tables seamlessly...
Support for parsing the mps oem tables is already there - I use it for
NUMA-Q ... see if smp_read_mpc_oem will do what you want ... if not,
maybe we can generalise it out.
> Also, could the clustered_logical and clustered_physical modes be
> implemented as a primary item, with NUMA being a secondary with the set of
> its unique features on top of the certain APIC mode? This way, a clustered
> mode for the APIC could be selectable without NUMA. CLUSTERED_APIC_NUMAQ
> could be still an option with an appropriate clustered mode defined.
Yup - it was only set up that way because we had a 1-1 correlation between
NUMA and clustered_apic_mode at the time. Switching the ordering as you
suggest seems sensible now.
In the last patch from Venkatesh there was a > 8CPUs option ... that
seems like a direct correlation to clustered apic support to me ...
maybe we could just switch on CONFIG_X86_CLUSTERED_APIC directly and
bypass CONFIG_X86_MANY_CPU? The menu text could stay the same (less
confusing for users than asking them about apic modes) ...
M.
At some point in the past, I wrote:
> >>IIRC NUMA-Q can be dynamically detected at boot by means of an MP OEM
> >>table's presence, in particular if there's a matching string in the 8B
> >>OEM record in the OEM table, with a value of "IBM NUMA" IIRC. This is
> >>probably a line or two's worth of change to mpparse.c and declaring a
> >>variable for clustered_apic_mode. If it were difficult to detect, I
> >>wouldn't have suggested implementing it (though do so at your leisure).
> >>=)
On Sun, Dec 22, 2002 at 01:01:54PM -0800, Martin J. Bligh wrote:
> I don't think you need the OEM table to detect this, current patches do:
>
> +static inline void mps_oem_check(struct mp_config_table *mpc, char *oem,
> + char *productid)
> +{
> + if (strncmp(oem, "IBM NUMA", 8))
> + printk("Warning! May not be a NUMA-Q system!\n");
Well, this is precisely what I meant by checking the OEM ID. It appears
to already be implemented in at least one set of patches, then. =)
Cheers,
Bill