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authorChristoph Lameter <clameter@engr.sgi.com>2007-05-06 14:48:58 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-07 12:12:51 -0700
commit476f35348eb8d2a827765992899fea78b7dcc46f (patch)
tree81dbace9de3d4ffa3ecc67bffe265134962117bd
parentaee16b3cee2746880e40945a9b5bff4f309cfbc4 (diff)
downloadlinux-476f35348eb8d2a827765992899fea78b7dcc46f.tar.gz
Safer nr_node_ids and nr_node_ids determination and initial values
The nr_cpu_ids value is currently only calculated in smp_init. However, it may be needed before (SLUB needs it on kmem_cache_init!) and other kernel components may also want to allocate dynamically sized per cpu array before smp_init. So move the determination of possible cpus into sched_init() where we already loop over all possible cpus early in boot. Also initialize both nr_node_ids and nr_cpu_ids with the highest value they could take. If we have accidental users before these values are determined then the current valud of 0 may cause too small per cpu and per node arrays to be allocated. If it is set to the maximum possible then we only waste some memory for early boot users. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--init/main.c5
-rw-r--r--kernel/sched.c8
-rw-r--r--lib/cpumask.c3
-rw-r--r--mm/page_alloc.c2
4 files changed, 9 insertions, 9 deletions
diff --git a/init/main.c b/init/main.c
index df982ff5d2b..0e22f40487b 100644
--- a/init/main.c
+++ b/init/main.c
@@ -384,11 +384,6 @@ static void __init setup_per_cpu_areas(void)
static void __init smp_init(void)
{
unsigned int cpu;
- unsigned highest = 0;
-
- for_each_cpu_mask(cpu, cpu_possible_map)
- highest = cpu;
- nr_cpu_ids = highest + 1;
/* FIXME: This should be done in userspace --RR */
for_each_present_cpu(cpu) {
diff --git a/kernel/sched.c b/kernel/sched.c
index 960d7c5fca3..0227f1625a7 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5244,6 +5244,11 @@ int __init migration_init(void)
#endif
#ifdef CONFIG_SMP
+
+/* Number of possible processor ids */
+int nr_cpu_ids __read_mostly = NR_CPUS;
+EXPORT_SYMBOL(nr_cpu_ids);
+
#undef SCHED_DOMAIN_DEBUG
#ifdef SCHED_DOMAIN_DEBUG
static void sched_domain_debug(struct sched_domain *sd, int cpu)
@@ -6726,6 +6731,7 @@ int in_sched_functions(unsigned long addr)
void __init sched_init(void)
{
int i, j, k;
+ int highest_cpu = 0;
for_each_possible_cpu(i) {
struct prio_array *array;
@@ -6760,11 +6766,13 @@ void __init sched_init(void)
// delimiter for bitsearch
__set_bit(MAX_PRIO, array->bitmap);
}
+ highest_cpu = i;
}
set_load_weight(&init_task);
#ifdef CONFIG_SMP
+ nr_cpu_ids = highest_cpu + 1;
open_softirq(SCHED_SOFTIRQ, run_rebalance_domains, NULL);
#endif
diff --git a/lib/cpumask.c b/lib/cpumask.c
index 1ea2c184315..bb4f76d3c3e 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -15,9 +15,6 @@ int __next_cpu(int n, const cpumask_t *srcp)
}
EXPORT_SYMBOL(__next_cpu);
-int nr_cpu_ids;
-EXPORT_SYMBOL(nr_cpu_ids);
-
int __any_online_cpu(const cpumask_t *mask)
{
int cpu;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 353ce9039a8..019ceda6a8b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -665,7 +665,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
}
#if MAX_NUMNODES > 1
-int nr_node_ids __read_mostly;
+int nr_node_ids __read_mostly = MAX_NUMNODES;
EXPORT_SYMBOL(nr_node_ids);
/*