sched: Aggregate load contributed by task entities on parenting cfs_rq

For a given task t, we can compute its contribution to load as:

  task_load(t) = runnable_avg(t) * weight(t)

On a parenting cfs_rq we can then aggregate:

  runnable_load(cfs_rq) = \Sum task_load(t), for all runnable children t

Maintain this bottom up, with task entities adding their contributed load to
the parenting cfs_rq sum.  When a task entity's load changes we add the same
delta to the maintained sum.

Signed-off-by: Paul Turner <pjt@google.com>
Reviewed-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120823141506.514678907@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 4240abce4116..c953a89f94aa 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -94,6 +94,7 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group
 #ifdef CONFIG_SMP
         P(se->avg.runnable_avg_sum);
         P(se->avg.runnable_avg_period);
+        P(se->avg.load_avg_contrib);
 #endif
 #undef PN
 #undef P
@@ -224,6 +225,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
                         cfs_rq->load_contribution);
         SEQ_printf(m, "  .%-30s: %d\n", "load_tg",
                         atomic_read(&cfs_rq->tg->load_weight));
+        SEQ_printf(m, "  .%-30s: %lld\n", "runnable_load_avg",
+                        cfs_rq->runnable_load_avg);
 #endif
 
         print_cfs_group_stats(m, cpu, cfs_rq->tg);