1 files changed, 54 insertions, 11 deletions

diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
index a5740fc4d04..457ed765a11 100644
--- a/include/linux/cpuset.h
+++ b/include/linux/cpuset.h
@@ -21,8 +21,7 @@ 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_cpus_allowed(struct task_struct *p, struct cpumask *mask);
-extern void cpuset_cpus_allowed_locked(struct task_struct *p,
-				       struct cpumask *mask);
+extern int cpuset_cpus_allowed_fallback(struct task_struct *p);
 extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
 #define cpuset_current_mems_allowed (current->mems_allowed)
 void cpuset_init_current_mems_allowed(void);
@@ -69,10 +68,8 @@ struct seq_file;
 extern void cpuset_task_status_allowed(struct seq_file *m,
 					struct task_struct *task);
 
-extern void cpuset_lock(void);
-extern void cpuset_unlock(void);
-
 extern int cpuset_mem_spread_node(void);
+extern int cpuset_slab_spread_node(void);
 
 static inline int cpuset_do_page_mem_spread(void)
 {
@@ -90,9 +87,44 @@ extern void rebuild_sched_domains(void);
 
 extern void cpuset_print_task_mems_allowed(struct task_struct *p);
 
+/*
+ * reading current mems_allowed and mempolicy in the fastpath must protected
+ * by get_mems_allowed()
+ */
+static inline void get_mems_allowed(void)
+{
+	current->mems_allowed_change_disable++;
+
+	/*
+	 * ensure that reading mems_allowed and mempolicy happens after the
+	 * update of ->mems_allowed_change_disable.
+	 *
+	 * the write-side task finds ->mems_allowed_change_disable is not 0,
+	 * and knows the read-side task is reading mems_allowed or mempolicy,
+	 * so it will clear old bits lazily.
+	 */
+	smp_mb();
+}
+
+static inline void put_mems_allowed(void)
+{
+	/*
+	 * ensure that reading mems_allowed and mempolicy before reducing
+	 * mems_allowed_change_disable.
+	 *
+	 * the write-side task will know that the read-side task is still
+	 * reading mems_allowed or mempolicy, don't clears old bits in the
+	 * nodemask.
+	 */
+	smp_mb();
+	--ACCESS_ONCE(current->mems_allowed_change_disable);
+}
+
 static inline void set_mems_allowed(nodemask_t nodemask)
 {
+	task_lock(current);
 	current->mems_allowed = nodemask;
+	task_unlock(current);
 }
 
 #else /* !CONFIG_CPUSETS */
@@ -105,10 +137,11 @@ static inline void cpuset_cpus_allowed(struct task_struct *p,
 {
 	cpumask_copy(mask, cpu_possible_mask);
 }
-static inline void cpuset_cpus_allowed_locked(struct task_struct *p,
-					      struct cpumask *mask)
+
+static inline int cpuset_cpus_allowed_fallback(struct task_struct *p)
 {
-	cpumask_copy(mask, cpu_possible_mask);
+	cpumask_copy(&p->cpus_allowed, cpu_possible_mask);
+	return cpumask_any(cpu_active_mask);
 }
 
 static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)
@@ -157,14 +190,16 @@ static inline void cpuset_task_status_allowed(struct seq_file *m,
 {
 }
 
-static inline void cpuset_lock(void) {}
-static inline void cpuset_unlock(void) {}
-
 static inline int cpuset_mem_spread_node(void)
 {
 	return 0;
 }
 
+static inline int cpuset_slab_spread_node(void)
+{
+	return 0;
+}
+
 static inline int cpuset_do_page_mem_spread(void)
 {
 	return 0;
@@ -193,6 +228,14 @@ static inline void set_mems_allowed(nodemask_t nodemask)
 {
 }
 
+static inline void get_mems_allowed(void)
+{
+}
+
+static inline void put_mems_allowed(void)
+{
+}
+
 #endif /* !CONFIG_CPUSETS */
 
 #endif /* _LINUX_CPUSET_H */