sched: Fully integrate cpus_active_map and root-domain code

Reflect "active" cpus in the rq->rd->online field, instead of
the online_map.

The motivation is that things that use the root-domain code
(such as cpupri) only care about cpus classified as "active"
anyway. By synchronizing the root-domain state with the active
map, we allow several optimizations.

For instance, we can remove an extra cpumask_and from the
scheduler hotpath by utilizing rq->rd->online (since it is now
a cached version of cpu_active_map & rq->rd->span).

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Max Krasnyansky <maxk@qualcomm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090730145723.25226.24493.stgit@dev.haskins.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 0 insertions, 7 deletions

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index a8f89bc3e5eb..13f728ef5b38 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1173,13 +1173,6 @@ static int find_lowest_rq(struct task_struct *task)
                 return -1; /* No targets found */
 
         /*
-         * Only consider CPUs that are usable for migration.
-         * I guess we might want to change cpupri_find() to ignore those
-         * in the first place.
-         */
-        cpumask_and(lowest_mask, lowest_mask, cpu_active_mask);
-
-        /*
          * At this point we have built a mask of cpus representing the
          * lowest priority tasks in the system.  Now we want to elect
          * the best one based on our affinity and topology.