From: "Andi Kleen" <ak@suse.de>
Separate AMD CMP detection from Hyper Threading detection. This cleans up the
code a bit and fixes some problems with high CPU IDs.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/x86_64/kernel/setup.c | 39 ++++++++++++++++++++++---------------
1 files changed, 24 insertions(+), 15 deletions(-)
diff -puN arch/x86_64/kernel/setup.c~x86_64-separate-amd-cmp-detection-from-hyper-threading arch/x86_64/kernel/setup.c
--- 25/arch/x86_64/kernel/setup.c~x86_64-separate-amd-cmp-detection-from-hyper-threading Wed Mar 23 15:38:15 2005
+++ 25-akpm/arch/x86_64/kernel/setup.c Wed Mar 23 15:38:15 2005
@@ -725,6 +725,25 @@ static void __init display_cacheinfo(str
}
}
+/*
+ * Detect CMP (multi core) CPUs.
+ * Don't set up smp_num_siblings here because we don't want
+ * the scheduler to use SMT heuristics.
+ * This uses the AMD specification. Intel CPUs currently don't set
+ * c->x86_num_cores, this will need to be changed later.
+ * TBD: tune the scheduler for multi core.
+ * TBD: This should handle SMT+CMP CPUs.
+ */
+static void __init detect_cmp(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_SMP
+ int cpu = smp_processor_id();
+ phys_proc_id[cpu] = c->x86_apicid;
+ if (c->x86_num_cores > 1) {
+ phys_proc_id[cpu] >>= hweight32(c->x86_num_cores - 1);
+ }
+#endif
+}
static int __init init_amd(struct cpuinfo_x86 *c)
{
@@ -768,6 +787,9 @@ static int __init init_amd(struct cpuinf
When using SRAT use mapping from SRAT. */
cpu = c->x86_apicid;
if (acpi_numa <= 0 && c->x86_num_cores > 1) {
+ /* There is a node id field in 80000001 EBX
+ but we assume the BIOS follows the AMD
+ recommendations. */
cpu_to_node[cpu] = cpu >> hweight32(c->x86_num_cores - 1);
if (!node_online(cpu_to_node[cpu]))
cpu_to_node[cpu] = first_node(node_online_map);
@@ -787,7 +809,7 @@ static void __init detect_ht(struct cpui
int index_lsb, index_msb, tmp;
int cpu = smp_processor_id();
- if (!cpu_has(c, X86_FEATURE_HT))
+ if (!cpu_has(c, X86_FEATURE_HT) || cpu_has(c, X86_FEATURE_CMP_LEGACY))
return;
cpuid(1, &eax, &ebx, &ecx, &edx);
@@ -826,19 +848,6 @@ static void __init detect_ht(struct cpui
}
#endif
}
-
-static void __init sched_cmp_hack(struct cpuinfo_x86 *c)
-{
-#ifdef CONFIG_SMP
- /* AMD dual core looks like HT but isn't really. Hide it from the
- scheduler. This works around problems with the domain scheduler.
- Also probably gives slightly better scheduling and disables
- SMT nice which is harmful on dual core.
- TBD tune the domain scheduler for dual core. */
- if (c->x86_vendor == X86_VENDOR_AMD && cpu_has(c, X86_FEATURE_CMP_LEGACY))
- smp_num_siblings = 1;
-#endif
-}
static void __init init_intel(struct cpuinfo_x86 *c)
{
@@ -984,7 +993,7 @@ void __init identify_cpu(struct cpuinfo_
select_idle_routine(c);
detect_ht(c);
- sched_cmp_hack(c);
+ detect_cmp(c);
/*
* On SMP, boot_cpu_data holds the common feature set between
_