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-rw-r--r--include/linux/cpuset.h10
-rw-r--r--kernel/cpuset.c12
2 files changed, 20 insertions, 2 deletions
diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
index 37d2dd7ca3e..34081c168af 100644
--- a/include/linux/cpuset.h
+++ b/include/linux/cpuset.h
@@ -14,6 +14,8 @@
#ifdef CONFIG_CPUSETS
+extern int number_of_cpusets; /* How many cpusets are defined in system? */
+
extern int cpuset_init(void);
extern void cpuset_init_smp(void);
extern void cpuset_fork(struct task_struct *p);
@@ -25,7 +27,13 @@ void cpuset_update_task_memory_state(void);
#define cpuset_nodes_subset_current_mems_allowed(nodes) \
nodes_subset((nodes), current->mems_allowed)
int cpuset_zonelist_valid_mems_allowed(struct zonelist *zl);
-extern int cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask);
+
+extern int __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask);
+static int inline cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
+{
+ return number_of_cpusets <= 1 || __cpuset_zone_allowed(z, gfp_mask);
+}
+
extern int cpuset_excl_nodes_overlap(const struct task_struct *p);
#define cpuset_memory_pressure_bump() \
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 8f764de3a9e..6004719f26e 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -56,6 +56,13 @@
#define CPUSET_SUPER_MAGIC 0x27e0eb
+/*
+ * Tracks how many cpusets are currently defined in system.
+ * When there is only one cpuset (the root cpuset) we can
+ * short circuit some hooks.
+ */
+int number_of_cpusets;
+
/* See "Frequency meter" comments, below. */
struct fmeter {
@@ -1664,6 +1671,7 @@ static long cpuset_create(struct cpuset *parent, const char *name, int mode)
down(&callback_sem);
list_add(&cs->sibling, &cs->parent->children);
+ number_of_cpusets++;
up(&callback_sem);
err = cpuset_create_dir(cs, name, mode);
@@ -1726,6 +1734,7 @@ static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry)
spin_unlock(&d->d_lock);
cpuset_d_remove_dir(d);
dput(d);
+ number_of_cpusets--;
up(&callback_sem);
if (list_empty(&parent->children))
check_for_release(parent, &pathbuf);
@@ -1769,6 +1778,7 @@ int __init cpuset_init(void)
root->d_inode->i_nlink++;
top_cpuset.dentry = root;
root->d_inode->i_op = &cpuset_dir_inode_operations;
+ number_of_cpusets = 1;
err = cpuset_populate_dir(root);
/* memory_pressure_enabled is in root cpuset only */
if (err == 0)
@@ -1982,7 +1992,7 @@ static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs)
* GFP_USER - only nodes in current tasks mems allowed ok.
**/
-int cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
+int __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
{
int node; /* node that zone z is on */
const struct cpuset *cs; /* current cpuset ancestors */