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authorYazen Ghannam <[email protected]>2017-02-05 11:50:22 +0100
committerIngo Molnar <[email protected]>2017-02-05 12:18:45 +0100
commit08b259631b5a1d912af4832847b5642f377d9101 (patch)
tree3a77b453bac2a4e76f4e12d1c40d4c07f3f3258d
parent79a8b9aa388b0620cc1d525d7c0f0d9a8a85e08e (diff)
x86/CPU/AMD: Fix Zen SMT topology
After: a33d331761bc ("x86/CPU/AMD: Fix Bulldozer topology") our SMT scheduling topology for Fam17h systems is broken, because the ThreadId is included in the ApicId when SMT is enabled. So, without further decoding cpu_core_id is unique for each thread rather than the same for threads on the same core. This didn't affect systems with SMT disabled. Make cpu_core_id be what it is defined to be. Signed-off-by: Yazen Ghannam <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: <[email protected]> # 4.9 Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
-rw-r--r--arch/x86/kernel/cpu/amd.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 20dc44d1e6be..2b4cf04239b6 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -319,6 +319,13 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
if (c->x86 == 0x15)
c->cu_id = ebx & 0xff;
+ if (c->x86 >= 0x17) {
+ c->cpu_core_id = ebx & 0xff;
+
+ if (smp_num_siblings > 1)
+ c->x86_max_cores /= smp_num_siblings;
+ }
+
/*
* We may have multiple LLCs if L3 caches exist, so check if we
* have an L3 cache by looking at the L3 cache CPUID leaf.