Merge branch 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6

[linux-2.6-omap-h63xx.git] / kernel / cpuset.c

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index f227bc1726906a52a803907299230f62b39edd84..3e00526f52ec14d56eb89ee1ab5c1a40fbed1331 100644 (file)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -843,37 +843,25 @@ static void cpuset_change_cpumask(struct task_struct *tsk,
 /**
  * update_tasks_cpumask - Update the cpumasks of tasks in the cpuset.
  * @cs: the cpuset in which each task's cpus_allowed mask needs to be changed
+ * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks()
  *
  * Called with cgroup_mutex held
  *
  * The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
  * calling callback functions for each.
  *
- * Return 0 if successful, -errno if not.
+ * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0
+ * if @heap != NULL.
  */
-static int update_tasks_cpumask(struct cpuset *cs)
+static void update_tasks_cpumask(struct cpuset *cs, struct ptr_heap *heap)
 {
        struct cgroup_scanner scan;
-       struct ptr_heap heap;
-       int retval;
-
-       /*
-        * cgroup_scan_tasks() will initialize heap->gt for us.
-        * heap_init() is still needed here for we should not change
-        * cs->cpus_allowed when heap_init() fails.
-        */
-       retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
-       if (retval)
-               return retval;
 
        scan.cg = cs->css.cgroup;
        scan.test_task = cpuset_test_cpumask;
        scan.process_task = cpuset_change_cpumask;
-       scan.heap = &heap;
-       retval = cgroup_scan_tasks(&scan);
-
-       heap_free(&heap);
-       return retval;
+       scan.heap = heap;
+       cgroup_scan_tasks(&scan);
 }
 
 /**
@@ -883,6 +871,7 @@ static int update_tasks_cpumask(struct cpuset *cs)
  */
 static int update_cpumask(struct cpuset *cs, const char *buf)
 {
+       struct ptr_heap heap;
        struct cpuset trialcs;
        int retval;
        int is_load_balanced;
@@ -917,6 +906,10 @@ static int update_cpumask(struct cpuset *cs, const char *buf)
        if (cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed))
                return 0;
 
+       retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
+       if (retval)
+               return retval;
+
        is_load_balanced = is_sched_load_balance(&trialcs);
 
        mutex_lock(&callback_mutex);
@@ -927,9 +920,9 @@ static int update_cpumask(struct cpuset *cs, const char *buf)
         * Scan tasks in the cpuset, and update the cpumasks of any
         * that need an update.
         */
-       retval = update_tasks_cpumask(cs);
-       if (retval < 0)
-               return retval;
+       update_tasks_cpumask(cs, &heap);
+
+       heap_free(&heap);
 
        if (is_load_balanced)
                async_rebuild_sched_domains();
@@ -1179,7 +1172,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
 {
        struct cpuset trialcs;
        int err;
-       int cpus_nonempty, balance_flag_changed;
+       int balance_flag_changed;
 
        trialcs = *cs;
        if (turning_on)
@@ -1191,7 +1184,6 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
        if (err < 0)
                return err;
 
-       cpus_nonempty = !cpus_empty(trialcs.cpus_allowed);
        balance_flag_changed = (is_sched_load_balance(cs) !=
                                        is_sched_load_balance(&trialcs));
 
@@ -1199,7 +1191,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
        cs->flags = trialcs.flags;
        mutex_unlock(&callback_mutex);
 
-       if (cpus_nonempty && balance_flag_changed)
+       if (!cpus_empty(trialcs.cpus_allowed) && balance_flag_changed)
                async_rebuild_sched_domains();
 
        return 0;
@@ -1928,7 +1920,7 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
  * that has tasks along with an empty 'mems'.  But if we did see such
  * a cpuset, we'd handle it just like we do if its 'cpus' was empty.
  */
-static void scan_for_empty_cpusets(const struct cpuset *root)
+static void scan_for_empty_cpusets(struct cpuset *root)
 {
        LIST_HEAD(queue);
        struct cpuset *cp;      /* scans cpusets being updated */
@@ -1965,7 +1957,7 @@ static void scan_for_empty_cpusets(const struct cpuset *root)
                     nodes_empty(cp->mems_allowed))
                        remove_tasks_in_empty_cpuset(cp);
                else {
-                       update_tasks_cpumask(cp);
+                       update_tasks_cpumask(cp, NULL);
                        update_tasks_nodemask(cp, &oldmems);
                }
        }
@@ -2444,19 +2436,15 @@ const struct file_operations proc_cpuset_operations = {
 void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task)
 {
        seq_printf(m, "Cpus_allowed:\t");
-       m->count += cpumask_scnprintf(m->buf + m->count, m->size - m->count,
-                                       task->cpus_allowed);
+       seq_cpumask(m, &task->cpus_allowed);
        seq_printf(m, "\n");
        seq_printf(m, "Cpus_allowed_list:\t");
-       m->count += cpulist_scnprintf(m->buf + m->count, m->size - m->count,
-                                       task->cpus_allowed);
+       seq_cpumask_list(m, &task->cpus_allowed);
        seq_printf(m, "\n");
        seq_printf(m, "Mems_allowed:\t");
-       m->count += nodemask_scnprintf(m->buf + m->count, m->size - m->count,
-                                       task->mems_allowed);
+       seq_nodemask(m, &task->mems_allowed);
        seq_printf(m, "\n");
        seq_printf(m, "Mems_allowed_list:\t");
-       m->count += nodelist_scnprintf(m->buf + m->count, m->size - m->count,
-                                       task->mems_allowed);
+       seq_nodemask_list(m, &task->mems_allowed);
        seq_printf(m, "\n");
 }