cpuset: modify cpuset_set_cpus_allowed to use cpumask pointer

  * Modify cpuset_cpus_allowed to return the currently allowed cpuset
    via a pointer argument instead of as the function return value.

  * Use new set_cpus_allowed_ptr function.

  * Cleanup CPU_MASK_ALL and NODE_MASK_ALL uses.

Depends on:
	[sched-devel]: sched: add new set_cpus_allowed_ptr function

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
index 0a26be353cb3763c8541ad3594bf6162f1a3b2ec..726761e2400365c1e5dc92d627dee8f2e06c837c 100644 (file)
--- a/include/linux/cpuset.h
+++ b/include/linux/cpuset.h
@@ -20,8 +20,8 @@ extern int number_of_cpusets; /* How many cpusets are defined in system? */
 extern int cpuset_init_early(void);
 extern int cpuset_init(void);
 extern void cpuset_init_smp(void);
-extern cpumask_t cpuset_cpus_allowed(struct task_struct *p);
-extern cpumask_t cpuset_cpus_allowed_locked(struct task_struct *p);
+extern void cpuset_cpus_allowed(struct task_struct *p, cpumask_t *mask);
+extern void cpuset_cpus_allowed_locked(struct task_struct *p, cpumask_t *mask);
 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);
@@ -84,13 +84,14 @@ static inline int cpuset_init_early(void) { return 0; }
 static inline int cpuset_init(void) { return 0; }
 static inline void cpuset_init_smp(void) {}
 
-static inline cpumask_t cpuset_cpus_allowed(struct task_struct *p)
+static inline void cpuset_cpus_allowed(struct task_struct *p, cpumask_t *mask)
 {
-       return cpu_possible_map;
+       *mask = cpu_possible_map;
 }
-static inline cpumask_t cpuset_cpus_allowed_locked(struct task_struct *p)
+static inline void cpuset_cpus_allowed_locked(struct task_struct *p,
+                                                               cpumask_t *mask)
 {
-       return cpu_possible_map;
+       *mask = cpu_possible_map;
 }
 
 static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index a1b61f414228ea031cc40ea9ea17ab95e264ceaf..6b9ac296a05cd7c68e22c53a3b3243d4ffdecd03 100644 (file)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -729,7 +729,7 @@ int cpuset_test_cpumask(struct task_struct *tsk, struct cgroup_scanner *scan)
  */
 void cpuset_change_cpumask(struct task_struct *tsk, struct cgroup_scanner *scan)
 {
-       set_cpus_allowed(tsk, (cgroup_cs(scan->cg))->cpus_allowed);
+       set_cpus_allowed_ptr(tsk, &((cgroup_cs(scan->cg))->cpus_allowed));
 }
 
 /**
@@ -1178,7 +1178,7 @@ static void cpuset_attach(struct cgroup_subsys *ss,
 
        mutex_lock(&callback_mutex);
        guarantee_online_cpus(cs, &cpus);
-       set_cpus_allowed(tsk, cpus);
+       set_cpus_allowed_ptr(tsk, &cpus);
        mutex_unlock(&callback_mutex);
 
        from = oldcs->mems_allowed;
@@ -1555,8 +1555,8 @@ static struct cgroup_subsys_state *cpuset_create(
        if (is_spread_slab(parent))
                set_bit(CS_SPREAD_SLAB, &cs->flags);
        set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
-       cs->cpus_allowed = CPU_MASK_NONE;
-       cs->mems_allowed = NODE_MASK_NONE;
+       cpus_clear(cs->cpus_allowed);
+       nodes_clear(cs->mems_allowed);
        cs->mems_generation = cpuset_mems_generation++;
        fmeter_init(&cs->fmeter);
 
@@ -1625,8 +1625,8 @@ int __init cpuset_init(void)
 {
        int err = 0;
 
-       top_cpuset.cpus_allowed = CPU_MASK_ALL;
-       top_cpuset.mems_allowed = NODE_MASK_ALL;
+       cpus_setall(top_cpuset.cpus_allowed);
+       nodes_setall(top_cpuset.mems_allowed);
 
        fmeter_init(&top_cpuset.fmeter);
        top_cpuset.mems_generation = cpuset_mems_generation++;
@@ -1844,6 +1844,7 @@ void __init cpuset_init_smp(void)
 
  * cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset.
  * @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed.
+ * @pmask: pointer to cpumask_t variable to receive cpus_allowed set.
  *
  * Description: Returns the cpumask_t cpus_allowed of the cpuset
  * attached to the specified @tsk.  Guaranteed to return some non-empty
@@ -1851,35 +1852,27 @@ void __init cpuset_init_smp(void)
  * tasks cpuset.
  **/
 
-cpumask_t cpuset_cpus_allowed(struct task_struct *tsk)
+void cpuset_cpus_allowed(struct task_struct *tsk, cpumask_t *pmask)
 {
-       cpumask_t mask;
-
        mutex_lock(&callback_mutex);
-       mask = cpuset_cpus_allowed_locked(tsk);
+       cpuset_cpus_allowed_locked(tsk, pmask);
        mutex_unlock(&callback_mutex);
-
-       return mask;
 }
 
 /**
  * cpuset_cpus_allowed_locked - return cpus_allowed mask from a tasks cpuset.
  * Must be called with callback_mutex held.
  **/
-cpumask_t cpuset_cpus_allowed_locked(struct task_struct *tsk)
+void cpuset_cpus_allowed_locked(struct task_struct *tsk, cpumask_t *pmask)
 {
-       cpumask_t mask;
-
        task_lock(tsk);
-       guarantee_online_cpus(task_cs(tsk), &mask);
+       guarantee_online_cpus(task_cs(tsk), pmask);
        task_unlock(tsk);
-
-       return mask;
 }
 
 void cpuset_init_current_mems_allowed(void)
 {
-       current->mems_allowed = NODE_MASK_ALL;
+       nodes_setall(current->mems_allowed);
 }
 
 /**

diff --git a/kernel/sched.c b/kernel/sched.c
index ef3f28b334eab4021c1c040e58be9cfd7ad7409f..ccc23a9cd264b73a50fae97f3b08ee741b99e605 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4941,13 +4941,13 @@ long sched_setaffinity(pid_t pid, cpumask_t new_mask)
        if (retval)
                goto out_unlock;
 
-       cpus_allowed = cpuset_cpus_allowed(p);
+       cpuset_cpus_allowed(p, &cpus_allowed);
        cpus_and(new_mask, new_mask, cpus_allowed);
  again:
        retval = set_cpus_allowed(p, new_mask);
 
        if (!retval) {
-               cpus_allowed = cpuset_cpus_allowed(p);
+               cpuset_cpus_allowed(p, &cpus_allowed);
                if (!cpus_subset(new_mask, cpus_allowed)) {
                        /*
                         * We must have raced with a concurrent cpuset
@@ -5661,7 +5661,9 @@ static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
 
                /* No more Mr. Nice Guy. */
                if (dest_cpu >= nr_cpu_ids) {
-                       cpumask_t cpus_allowed = cpuset_cpus_allowed_locked(p);
+                       cpumask_t cpus_allowed;
+
+                       cpuset_cpus_allowed_locked(p, &cpus_allowed);
                        /*
                         * Try to stay on the same cpuset, where the
                         * current cpuset may be a subset of all cpus.

diff --git a/mm/pdflush.c b/mm/pdflush.c
index 8f6ee073c0e3f44a14a40fe1351006b1246e4523..0ceacff56457d10c607a36a51da040af806465d4 100644 (file)
--- a/mm/pdflush.c
+++ b/mm/pdflush.c
@@ -187,8 +187,8 @@ static int pdflush(void *dummy)
         * This is needed as pdflush's are dynamically created and destroyed.
         * The boottime pdflush's are easily placed w/o these 2 lines.
         */
-       cpus_allowed = cpuset_cpus_allowed(current);
-       set_cpus_allowed(current, cpus_allowed);
+       cpuset_cpus_allowed(current, &cpus_allowed);
+       set_cpus_allowed_ptr(current, &cpus_allowed);
 
        return __pdflush(&my_work);
 }