[PATCH] sched: make idlest_group/cpu cpus_allowed-aware

Add relevant checks into find_idlest_group() and find_idlest_cpu() to make
them return only the groups that have allowed CPUs and allowed CPUs
respectively.

Signed-off-by: M.Baris Demiray <baris@labristeknoloji.com>
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/kernel/sched.c b/kernel/sched.c
index ef748e6..bac23fb 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -966,8 +966,11 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
                int local_group;
                int i;
 
+               /* Skip over this group if it has no CPUs allowed */
+               if (!cpus_intersects(group->cpumask, p->cpus_allowed))
+                       goto nextgroup;
+
                local_group = cpu_isset(this_cpu, group->cpumask);
-               /* XXX: put a cpus allowed check */
 
                /* Tally up the load of all CPUs in the group */
                avg_load = 0;
@@ -992,6 +995,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
                        min_load = avg_load;
                        idlest = group;
                }
+nextgroup:
                group = group->next;
        } while (group != sd->groups);
 
@@ -1003,13 +1007,18 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
 /*
  * find_idlest_queue - find the idlest runqueue among the cpus in group.
  */
-static int find_idlest_cpu(struct sched_group *group, int this_cpu)
+static int find_idlest_cpu(struct sched_group *group,
+                       struct task_struct *p, int this_cpu)
 {
+       cpumask_t tmp;
        unsigned long load, min_load = ULONG_MAX;
        int idlest = -1;
        int i;
 
-       for_each_cpu_mask(i, group->cpumask) {
+       /* Traverse only the allowed CPUs */
+       cpus_and(tmp, group->cpumask, p->cpus_allowed);
+
+       for_each_cpu_mask(i, tmp) {
                load = source_load(i, 0);
 
                if (load < min_load || (load == min_load && i == this_cpu)) {
@@ -1052,7 +1061,7 @@ static int sched_balance_self(int cpu, int flag)
                if (!group)
                        goto nextlevel;
 
-               new_cpu = find_idlest_cpu(group, cpu);
+               new_cpu = find_idlest_cpu(group, t, cpu);
                if (new_cpu == -1 || new_cpu == cpu)
                        goto nextlevel;