On NumaChip systems, the physical processor ID assignment wasn't accounting
for the number of nodes in AMD multi-module processors, giving an incorrect
sibling map:
$ cd /sys/devices/system/cpu/cpu29/topology
$ grep . *
core_id:5
core_siblings:00000000,ff000000
core_siblings_list:24-31
physical_package_id:3
thread_siblings:00000000,30000000
thread_siblings_list:28-29
After fixing:
core_id:5
core_siblings:00000000,ffff0000
core_siblings_list:16-31
physical_package_id:1
thread_siblings:00000000,30000000
thread_siblings_list:28-29
v2: Fix to check for MSR availability before use, as per Boris's feedback
v3: Test against boot cpu features to correct behaviour on larger systems
with global IO
Candidate for stable.
Signed-off-by: Daniel J Blueman <dan...@numascale.com>
---
arch/x86/kernel/apic/apic_numachip.c | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/apic/apic_numachip.c
b/arch/x86/kernel/apic/apic_numachip.c
index c2fd21f..c1f4f36 100644
--- a/arch/x86/kernel/apic/apic_numachip.c
+++ b/arch/x86/kernel/apic/apic_numachip.c
@@ -37,10 +37,12 @@ static const struct apic apic_numachip;
static unsigned int get_apic_id(unsigned long x)
{
unsigned long value;
- unsigned int id;
+ unsigned int id = (x >> 24) & 0xff;
- rdmsrl(MSR_FAM10H_NODE_ID, value);
- id = ((x >> 24) & 0xffU) | ((value << 2) & 0xff00U);
+ if (boot_cpu_has(X86_FEATURE_NODEID_MSR)) {
+ rdmsrl(MSR_FAM10H_NODE_ID, value);
+ id |= (value << 2) & 0xff00;
+ }
return id;
}
@@ -155,10 +157,18 @@ static int __init numachip_probe(void)
static void fixup_cpu_id(struct cpuinfo_x86 *c, int node)
{
- if (c->phys_proc_id != node) {
- c->phys_proc_id = node;
- per_cpu(cpu_llc_id, smp_processor_id()) = node;
+ u64 val;
+ u32 nodes = 1;
+
+ this_cpu_write(cpu_llc_id, node);
+
+ /* Account for nodes per socket in multi-core-module processors */
+ if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
+ rdmsrl(MSR_FAM10H_NODE_ID, val);
+ nodes = ((val >> 3) & 7) + 1;
}
+
+ c->phys_proc_id = node / nodes;
}
static int __init numachip_system_init(void)
--
1.9.1
--
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