Commit-ID: 155dd720d06a219ddf5a56b473cb3325441fc879
Gitweb: http://git.kernel.org/tip/155dd720d06a219ddf5a56b473cb3325441fc879
Author: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
AuthorDate: Fri, 13 Mar 2009 14:49:53 +1030
Commit: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
CommitDate: Fri, 13 Mar 2009 14:49:53 +1030
cpumask: convert struct cpuinfo_x86's llc_shared_map to cpumask_var_t
Impact: reduce kernel memory usage when CONFIG_CPUMASK_OFFSTACK=y
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/processor.h | 2 +-
arch/x86/kernel/smpboot.c | 33 ++++++++++++++++++++++++++-------
2 files changed, 27 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 7613950..d794d94 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -94,7 +94,7 @@ struct cpuinfo_x86 {
unsigned long loops_per_jiffy;
#ifdef CONFIG_SMP
/* cpus sharing the last level cache: */
- cpumask_t llc_shared_map;
+ cpumask_var_t llc_shared_map;
#endif
/* cpuid returned max cores value: */
u16 x86_max_cores;
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 5a58a45..d6427aa 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -329,6 +329,23 @@ notrace static void __cpuinit start_secondary(void *unused)
cpu_idle();
}
+#ifdef CONFIG_CPUMASK_OFFSTACK
+/* In this case, llc_shared_map is a pointer to a cpumask. */
+static inline void copy_cpuinfo_x86(struct cpuinfo_x86 *dst,
+ const struct cpuinfo_x86 *src)
+{
+ struct cpumask *llc = dst->llc_shared_map;
+ *dst = *src;
+ dst->llc_shared_map = llc;
+}
+#else
+static inline void copy_cpuinfo_x86(struct cpuinfo_x86 *dst,
+ const struct cpuinfo_x86 *src)
+{
+ *dst = *src;
+}
+#endif /* CONFIG_CPUMASK_OFFSTACK */
+
/*
* The bootstrap kernel entry code has set these up. Save them for
* a given CPU
@@ -338,7 +355,7 @@ void __cpuinit smp_store_cpu_info(int id)
{
struct cpuinfo_x86 *c = &cpu_data(id);
- *c = boot_cpu_data;
+ copy_cpuinfo_x86(c, &boot_cpu_data);
c->cpu_index = id;
if (id != 0)
identify_secondary_cpu(c);
@@ -362,15 +379,15 @@ void __cpuinit set_cpu_sibling_map(int cpu)
cpumask_set_cpu(cpu, cpu_sibling_mask(i));
cpumask_set_cpu(i, cpu_core_mask(cpu));
cpumask_set_cpu(cpu, cpu_core_mask(i));
- cpumask_set_cpu(i, &c->llc_shared_map);
- cpumask_set_cpu(cpu, &o->llc_shared_map);
+ cpumask_set_cpu(i, c->llc_shared_map);
+ cpumask_set_cpu(cpu, o->llc_shared_map);
}
}
} else {
cpumask_set_cpu(cpu, cpu_sibling_mask(cpu));
}
- cpumask_set_cpu(cpu, &c->llc_shared_map);
+ cpumask_set_cpu(cpu, c->llc_shared_map);
if (current_cpu_data.x86_max_cores == 1) {
cpumask_copy(cpu_core_mask(cpu), cpu_sibling_mask(cpu));
@@ -381,8 +398,8 @@ void __cpuinit set_cpu_sibling_map(int cpu)
for_each_cpu(i, cpu_sibling_setup_mask) {
if (per_cpu(cpu_llc_id, cpu) != BAD_APICID &&
per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) {
- cpumask_set_cpu(i, &c->llc_shared_map);
- cpumask_set_cpu(cpu, &cpu_data(i).llc_shared_map);
+ cpumask_set_cpu(i, c->llc_shared_map);
+ cpumask_set_cpu(cpu, cpu_data(i).llc_shared_map);
}
if (c->phys_proc_id == cpu_data(i).phys_proc_id) {
cpumask_set_cpu(i, cpu_core_mask(cpu));
@@ -420,7 +437,7 @@ const struct cpumask *cpu_coregroup_mask(int cpu)
if (sched_mc_power_savings || sched_smt_power_savings)
return cpu_core_mask(cpu);
else
- return &c->llc_shared_map;
+ return c->llc_shared_map;
}
static void impress_friends(void)
@@ -1039,8 +1056,10 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
for_each_possible_cpu(i) {
alloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
alloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
+ alloc_cpumask_var(&cpu_data(i).llc_shared_map, GFP_KERNEL);
cpumask_clear(per_cpu(cpu_core_map, i));
cpumask_clear(per_cpu(cpu_sibling_map, i));
+ cpumask_clear(cpu_data(i).llc_shared_map);
}
set_cpu_sibling_map(0);
--
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