Re: [PATCH] x86: use hard_smp_processor_id to get apic id in identify_cpu-v2

From: Yinghai Lu
Date: Wed Aug 26 2009 - 15:08:53 EST

Suresh Siddha wrote:
> In short, on all the platforms we want to use initial apic id for apicid
> and phys_proc_id. And only on the required platforms like x445, vsmp,
> some AMD platforms, we can have their own mechanisms.
>> 3. for vsmp, and x445, do you want to have c->apicid to have real apic id or the same as initial apic_id?
> On these platforms, c->apicid should be based on their real apic id.
>> this patch is trying to make c->apicid to have real apic_id.
> Can you please modify the patch so that we can have exceptions for
> needed platforms only?

please check this one

[PATCH] x86: use hard_smp_processor_id to get apic id for amd k8 cpus

otherwise, system with apci id lifting will have wrong apicid in

and use that in srat_detect_node

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>

arch/x86/kernel/cpu/amd.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

Index: linux-2.6/arch/x86/kernel/cpu/amd.c
--- linux-2.6.orig/arch/x86/kernel/cpu/amd.c
+++ linux-2.6/arch/x86/kernel/cpu/amd.c
@@ -277,7 +277,7 @@ static void __cpuinit srat_detect_node(s
#if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
int cpu = smp_processor_id();
int node;
- unsigned apicid = cpu_has_apic ? hard_smp_processor_id() : c->apicid;
+ unsigned apicid = c->apicid;

node = c->phys_proc_id;
if (apicid_to_node[apicid] != NUMA_NO_NODE)
@@ -437,6 +437,9 @@ static void __cpuinit init_amd(struct cp
if (c->x86 == 0x10 || c->x86 == 0x11)
set_cpu_cap(c, X86_FEATURE_REP_GOOD);
+ /* get apicid instead of initial apic id from cpuid */
+ c->apicid = hard_smp_processor_id();

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at