Convert cpu_sibling_map to be a per cpu variable
Convert cpu_sibling_map from a static array sized by NR_CPUS to a per_cpu
variable. This saves sizeof(cpumask_t) * NR unused cpus. Access is mostly
from startup and CPU HOTPLUG functions.
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 36c90ba..2de00f8 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -413,16 +413,28 @@
of_node_put(dn);
}
+ vdso_data->processorCount = num_present_cpus();
+#endif /* CONFIG_PPC64 */
+}
+
+/*
+ * Being that cpu_sibling_map is now a per_cpu array, then it cannot
+ * be initialized until the per_cpu areas have been created. This
+ * function is now called from setup_per_cpu_areas().
+ */
+void __init smp_setup_cpu_sibling_map(void)
+{
+#if defined(CONFIG_PPC64)
+ int cpu;
+
/*
* Do the sibling map; assume only two threads per processor.
*/
for_each_possible_cpu(cpu) {
- cpu_set(cpu, cpu_sibling_map[cpu]);
+ cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
if (cpu_has_feature(CPU_FTR_SMT))
- cpu_set(cpu ^ 0x1, cpu_sibling_map[cpu]);
+ cpu_set(cpu ^ 0x1, per_cpu(cpu_sibling_map, cpu));
}
-
- vdso_data->processorCount = num_present_cpus();
#endif /* CONFIG_PPC64 */
}
#endif /* CONFIG_SMP */
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 008ab68..0e014550 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -597,6 +597,9 @@
paca[i].data_offset = ptr - __per_cpu_start;
memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
}
+
+ /* Now that per_cpu is setup, initialize cpu_sibling_map */
+ smp_setup_cpu_sibling_map();
}
#endif
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index d30f08f..338950a 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -61,11 +61,11 @@
cpumask_t cpu_possible_map = CPU_MASK_NONE;
cpumask_t cpu_online_map = CPU_MASK_NONE;
-cpumask_t cpu_sibling_map[NR_CPUS] = { [0 ... NR_CPUS-1] = CPU_MASK_NONE };
+DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE;
EXPORT_SYMBOL(cpu_online_map);
EXPORT_SYMBOL(cpu_possible_map);
-EXPORT_SYMBOL(cpu_sibling_map);
+EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
/* SMP operations for this machine */
struct smp_ops_t *smp_ops;