sched: Make find_busiest_queue() a method

Its a bit awkward but it was the least painful means of modifying the
queue selection. Used in a later patch to conditionally use a random
queue.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Turner <pjt@google.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Link: http://lkml.kernel.org/n/tip-lfpez319yryvdhwqfqrh99f2@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 59e072b2db970b80eb2eac7b435d297305640e2a..511fbb8e65ea956c9b4eb6e04b68a919e12a96a4 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3600,6 +3600,9 @@ struct lb_env {
        unsigned int            loop;
        unsigned int            loop_break;
        unsigned int            loop_max;
+
+       struct rq *             (*find_busiest_queue)(struct lb_env *,
+                                                     struct sched_group *);
 };
 
 /*
@@ -4779,13 +4782,14 @@ static int load_balance(int this_cpu, struct rq *this_rq,
        struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
 
        struct lb_env env = {
-               .sd             = sd,
-               .dst_cpu        = this_cpu,
-               .dst_rq         = this_rq,
-               .dst_grpmask    = sched_group_cpus(sd->groups),
-               .idle           = idle,
-               .loop_break     = sched_nr_migrate_break,
-               .cpus           = cpus,
+               .sd                 = sd,
+               .dst_cpu            = this_cpu,
+               .dst_rq             = this_rq,
+               .dst_grpmask        = sched_group_cpus(sd->groups),
+               .idle               = idle,
+               .loop_break         = sched_nr_migrate_break,
+               .cpus               = cpus,
+               .find_busiest_queue = find_busiest_queue,
        };
 
        cpumask_copy(cpus, cpu_active_mask);
@@ -4804,7 +4808,7 @@ redo:
                goto out_balanced;
        }
 
-       busiest = find_busiest_queue(&env, group);
+       busiest = env.find_busiest_queue(&env, group);
        if (!busiest) {
                schedstat_inc(sd, lb_nobusyq[idle]);
                goto out_balanced;