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authorSrivatsa Vaddagiri <vatsa@in.ibm.com>2006-06-27 02:54:41 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-27 17:32:45 -0700
commit369381694ddcf03f1de403501c8b97099b5109ec (patch)
tree3945620740cc1687c8487356bf4be90394695702 /kernel/sched.c
parent15f0b676a482fb4067cfe25de417c417dda3440a (diff)
[PATCH] sched_domai: Allocate sched_group structures dynamically
As explained here: http://marc.theaimsgroup.com/?l=linux-kernel&m=114327539012323&w=2 there is a problem with sharing sched_group structures between two separate sched_group structures for different sched_domains. The patch has been tested and found to avoid the kernel lockup problem described in above URL. Signed-off-by: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c48
1 files changed, 43 insertions, 5 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index ee4211bd40c..122b75584a1 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5747,7 +5747,7 @@ static int cpu_to_cpu_group(int cpu)
#ifdef CONFIG_SCHED_MC
static DEFINE_PER_CPU(struct sched_domain, core_domains);
-static struct sched_group sched_group_core[NR_CPUS];
+static struct sched_group *sched_group_core_bycpu[NR_CPUS];
#endif
#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
@@ -5763,7 +5763,7 @@ static int cpu_to_core_group(int cpu)
#endif
static DEFINE_PER_CPU(struct sched_domain, phys_domains);
-static struct sched_group sched_group_phys[NR_CPUS];
+static struct sched_group *sched_group_phys_bycpu[NR_CPUS];
static int cpu_to_phys_group(int cpu)
{
#if defined(CONFIG_SCHED_MC)
@@ -5823,9 +5823,9 @@ next_sg:
/* Free memory allocated for various sched_group structures */
static void free_sched_groups(const cpumask_t *cpu_map)
{
+ int cpu;
#ifdef CONFIG_NUMA
int i;
- int cpu;
for_each_cpu_mask(cpu, *cpu_map) {
struct sched_group *sched_group_allnodes
@@ -5863,6 +5863,18 @@ next_sg:
sched_group_nodes_bycpu[cpu] = NULL;
}
#endif
+ for_each_cpu_mask(cpu, *cpu_map) {
+ if (sched_group_phys_bycpu[cpu]) {
+ kfree(sched_group_phys_bycpu[cpu]);
+ sched_group_phys_bycpu[cpu] = NULL;
+ }
+#ifdef CONFIG_SCHED_MC
+ if (sched_group_core_bycpu[cpu]) {
+ kfree(sched_group_core_bycpu[cpu]);
+ sched_group_core_bycpu[cpu] = NULL;
+ }
+#endif
+ }
}
/*
@@ -5872,6 +5884,10 @@ next_sg:
static int build_sched_domains(const cpumask_t *cpu_map)
{
int i;
+ struct sched_group *sched_group_phys = NULL;
+#ifdef CONFIG_SCHED_MC
+ struct sched_group *sched_group_core = NULL;
+#endif
#ifdef CONFIG_NUMA
struct sched_group **sched_group_nodes = NULL;
struct sched_group *sched_group_allnodes = NULL;
@@ -5930,6 +5946,18 @@ static int build_sched_domains(const cpumask_t *cpu_map)
cpus_and(sd->span, sd->span, *cpu_map);
#endif
+ if (!sched_group_phys) {
+ sched_group_phys
+ = kmalloc(sizeof(struct sched_group) * NR_CPUS,
+ GFP_KERNEL);
+ if (!sched_group_phys) {
+ printk (KERN_WARNING "Can not alloc phys sched"
+ "group\n");
+ goto error;
+ }
+ sched_group_phys_bycpu[i] = sched_group_phys;
+ }
+
p = sd;
sd = &per_cpu(phys_domains, i);
group = cpu_to_phys_group(i);
@@ -5939,6 +5967,18 @@ static int build_sched_domains(const cpumask_t *cpu_map)
sd->groups = &sched_group_phys[group];
#ifdef CONFIG_SCHED_MC
+ if (!sched_group_core) {
+ sched_group_core
+ = kmalloc(sizeof(struct sched_group) * NR_CPUS,
+ GFP_KERNEL);
+ if (!sched_group_core) {
+ printk (KERN_WARNING "Can not alloc core sched"
+ "group\n");
+ goto error;
+ }
+ sched_group_core_bycpu[i] = sched_group_core;
+ }
+
p = sd;
sd = &per_cpu(core_domains, i);
group = cpu_to_core_group(i);
@@ -6134,11 +6174,9 @@ static int build_sched_domains(const cpumask_t *cpu_map)
return 0;
-#ifdef CONFIG_NUMA
error:
free_sched_groups(cpu_map);
return -ENOMEM;
-#endif
}
/*
* Set up scheduler domains and groups. Callers must hold the hotplug lock.