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| author | Peter Zijlstra <peterz@infradead.org> | 2016-03-25 15:52:34 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-03-29 10:45:04 +0200 |
| commit | ee6825c80e870fff1a370c718ec77022ade0889b (patch) | |
| tree | ea5476978095b97d911d00e5a21c1c769c7f401a /arch/x86/kernel/cpu | |
| parent | Linux 4.6-rc1 (diff) | |
| download | linux-ee6825c80e870fff1a370c718ec77022ade0889b.tar.xz linux-ee6825c80e870fff1a370c718ec77022ade0889b.zip | |
x86/topology: Fix AMD core count
It turns out AMD gets x86_max_cores wrong when there are compute
units.
The issue is that Linux assumes:
nr_logical_cpus = nr_cores * nr_siblings
But AMD reports its CU unit as 2 cores, but then sets num_smp_siblings
to 2 as well.
Boris: fixup ras/mce_amd_inj.c too, to compute the Node Base Core
properly, according to the new nomenclature.
Fixes: 1f12e32f4cd5 ("x86/topology: Create logical package id")
Reported-by: Xiong Zhou <jencce.kernel@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andreas Herrmann <aherrmann@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/20160317095220.GO6344@twins.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/cpu')
| -rw-r--r-- | arch/x86/kernel/cpu/amd.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 6e47e3a916f1..4d0087f94ee5 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -312,9 +312,9 @@ static void amd_get_topology(struct cpuinfo_x86 *c) node_id = ecx & 7; /* get compute unit information */ - smp_num_siblings = ((ebx >> 8) & 3) + 1; + cores_per_cu = smp_num_siblings = ((ebx >> 8) & 3) + 1; + c->x86_max_cores /= smp_num_siblings; c->compute_unit_id = ebx & 0xff; - cores_per_cu += ((ebx >> 8) & 3); } else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) { u64 value; @@ -329,8 +329,8 @@ static void amd_get_topology(struct cpuinfo_x86 *c) u32 cus_per_node; set_cpu_cap(c, X86_FEATURE_AMD_DCM); - cores_per_node = c->x86_max_cores / nodes_per_socket; - cus_per_node = cores_per_node / cores_per_cu; + cus_per_node = c->x86_max_cores / nodes_per_socket; + cores_per_node = cus_per_node * cores_per_cu; /* store NodeID, use llc_shared_map to store sibling info */ per_cpu(cpu_llc_id, cpu) = node_id; |