sched: using dst_rq instead of this_rq during load balance

As we already have dst_rq in lb_env, using or changing "this_rq" do not
make sense.

This patch will replace "this_rq" with dst_rq in load_balance, and we
don't need to change "this_rq" while process LBF_SOME_PINNED any more.

Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/501F8357.3070102@linux.vnet.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 99285a8..287bfac 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4283,7 +4283,7 @@ redo:
                goto out_balanced;
        }
 
-       BUG_ON(busiest == this_rq);
+       BUG_ON(busiest == env.dst_rq);
 
        schedstat_add(sd, lb_imbalance[idle], env.imbalance);
 
@@ -4304,7 +4304,7 @@ redo:
                update_h_load(env.src_cpu);
 more_balance:
                local_irq_save(flags);
-               double_rq_lock(this_rq, busiest);
+               double_rq_lock(env.dst_rq, busiest);
 
                /*
                 * cur_ld_moved - load moved in current iteration
@@ -4312,7 +4312,7 @@ more_balance:
                 */
                cur_ld_moved = move_tasks(&env);
                ld_moved += cur_ld_moved;
-               double_rq_unlock(this_rq, busiest);
+               double_rq_unlock(env.dst_rq, busiest);
                local_irq_restore(flags);
 
                if (env.flags & LBF_NEED_BREAK) {
@@ -4348,8 +4348,7 @@ more_balance:
                if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0 &&
                                lb_iterations++ < max_lb_iterations) {
 
-                       this_rq          = cpu_rq(env.new_dst_cpu);
-                       env.dst_rq       = this_rq;
+                       env.dst_rq       = cpu_rq(env.new_dst_cpu);
                        env.dst_cpu      = env.new_dst_cpu;
                        env.flags       &= ~LBF_SOME_PINNED;
                        env.loop         = 0;