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authorRusty Russell <rusty@rustcorp.com.au>2008-11-24 16:05:13 (GMT)
committerIngo Molnar <mingo@elte.hu>2008-11-24 16:52:22 (GMT)
commit68e74568fbe5854952355e942acca51f138096d9 (patch)
tree6263627b3b3c7e249f685ba0fe4d76002e882cd0
parent4212823fb459eacc8098dd420bb68ebb9917989d (diff)
downloadlinux-68e74568fbe5854952355e942acca51f138096d9.tar.xz
sched: convert struct cpupri_vec cpumask_var_t.
Impact: stack usage reduction, (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. The fact cpupro_init is called both before and after the slab is available makes for an ugly parameter unfortunately. We also use cpumask_any_and to get rid of a temporary in cpupri_find. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/sched.c9
-rw-r--r--kernel/sched_cpupri.c39
-rw-r--r--kernel/sched_cpupri.h5
3 files changed, 38 insertions, 15 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 42588ad..94fa333 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6792,6 +6792,8 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
static void free_rootdomain(struct root_domain *rd)
{
+ cpupri_cleanup(&rd->cpupri);
+
free_cpumask_var(rd->rto_mask);
free_cpumask_var(rd->online);
free_cpumask_var(rd->span);
@@ -6834,7 +6836,7 @@ static int init_rootdomain(struct root_domain *rd, bool bootmem)
alloc_bootmem_cpumask_var(&def_root_domain.span);
alloc_bootmem_cpumask_var(&def_root_domain.online);
alloc_bootmem_cpumask_var(&def_root_domain.rto_mask);
- cpupri_init(&rd->cpupri);
+ cpupri_init(&rd->cpupri, true);
return 0;
}
@@ -6845,9 +6847,12 @@ static int init_rootdomain(struct root_domain *rd, bool bootmem)
if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
goto free_online;
- cpupri_init(&rd->cpupri);
+ if (cpupri_init(&rd->cpupri, false) != 0)
+ goto free_rto_mask;
return 0;
+free_rto_mask:
+ free_cpumask_var(rd->rto_mask);
free_online:
free_cpumask_var(rd->online);
free_span:
diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c
index 52154fe..018b7be 100644
--- a/kernel/sched_cpupri.c
+++ b/kernel/sched_cpupri.c
@@ -67,24 +67,21 @@ static int convert_prio(int prio)
* Returns: (int)bool - CPUs were found
*/
int cpupri_find(struct cpupri *cp, struct task_struct *p,
- cpumask_t *lowest_mask)
+ struct cpumask *lowest_mask)
{
int idx = 0;
int task_pri = convert_prio(p->prio);
for_each_cpupri_active(cp->pri_active, idx) {
struct cpupri_vec *vec = &cp->pri_to_cpu[idx];
- cpumask_t mask;
if (idx >= task_pri)
break;
- cpus_and(mask, p->cpus_allowed, vec->mask);
-
- if (cpus_empty(mask))
+ if (cpumask_any_and(&p->cpus_allowed, vec->mask) >= nr_cpu_ids)
continue;
- *lowest_mask = mask;
+ cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask);
return 1;
}
@@ -126,7 +123,7 @@ void cpupri_set(struct cpupri *cp, int cpu, int newpri)
vec->count--;
if (!vec->count)
clear_bit(oldpri, cp->pri_active);
- cpu_clear(cpu, vec->mask);
+ cpumask_clear_cpu(cpu, vec->mask);
spin_unlock_irqrestore(&vec->lock, flags);
}
@@ -136,7 +133,7 @@ void cpupri_set(struct cpupri *cp, int cpu, int newpri)
spin_lock_irqsave(&vec->lock, flags);
- cpu_set(cpu, vec->mask);
+ cpumask_set_cpu(cpu, vec->mask);
vec->count++;
if (vec->count == 1)
set_bit(newpri, cp->pri_active);
@@ -150,10 +147,11 @@ void cpupri_set(struct cpupri *cp, int cpu, int newpri)
/**
* cpupri_init - initialize the cpupri structure
* @cp: The cpupri context
+ * @bootmem: true if allocations need to use bootmem
*
- * Returns: (void)
+ * Returns: -ENOMEM if memory fails.
*/
-void cpupri_init(struct cpupri *cp)
+int cpupri_init(struct cpupri *cp, bool bootmem)
{
int i;
@@ -164,11 +162,30 @@ void cpupri_init(struct cpupri *cp)
spin_lock_init(&vec->lock);
vec->count = 0;
- cpus_clear(vec->mask);
+ if (bootmem)
+ alloc_bootmem_cpumask_var(&vec->mask);
+ else if (!alloc_cpumask_var(&vec->mask, GFP_KERNEL))
+ goto cleanup;
}
for_each_possible_cpu(i)
cp->cpu_to_pri[i] = CPUPRI_INVALID;
+ return 0;
+
+cleanup:
+ for (i--; i >= 0; i--)
+ free_cpumask_var(cp->pri_to_cpu[i].mask);
+ return -ENOMEM;
}
+/**
+ * cpupri_cleanup - clean up the cpupri structure
+ * @cp: The cpupri context
+ */
+void cpupri_cleanup(struct cpupri *cp)
+{
+ int i;
+ for (i = 0; i < CPUPRI_NR_PRIORITIES; i++)
+ free_cpumask_var(cp->pri_to_cpu[i].mask);
+}
diff --git a/kernel/sched_cpupri.h b/kernel/sched_cpupri.h
index f25811b0..642a94e 100644
--- a/kernel/sched_cpupri.h
+++ b/kernel/sched_cpupri.h
@@ -14,7 +14,7 @@
struct cpupri_vec {
spinlock_t lock;
int count;
- cpumask_t mask;
+ cpumask_var_t mask;
};
struct cpupri {
@@ -27,7 +27,8 @@ struct cpupri {
int cpupri_find(struct cpupri *cp,
struct task_struct *p, cpumask_t *lowest_mask);
void cpupri_set(struct cpupri *cp, int cpu, int pri);
-void cpupri_init(struct cpupri *cp);
+int cpupri_init(struct cpupri *cp, bool bootmem);
+void cpupri_cleanup(struct cpupri *cp);
#else
#define cpupri_set(cp, cpu, pri) do { } while (0)
#define cpupri_init() do { } while (0)