On 07/07/15 12:17, Rabin Vincent wrote:
> On Mon, Jul 06, 2015 at 07:36:56PM +0200, Dietmar Eggemann wrote:
>> Rabin, could you share the content of your
>> /sys/fs/cgroup/cpu/system.slice directory and of /proc/cgroups ?
>
> Here's /proc/cgroups,
>
> # cat /proc/cgroups
> #subsys_name hierarchy num_cgroups enabled
> cpu 2 98 1
> cpuacct 2 98 1
>
> and the contents of /sys/fs/cgroup/cpu/system.slice are available here:
> https://drive.google.com/file/d/0B4tMLbMvJ-l6ZVBvZ09QOE15MU0/view
>
> /Rabin
>
So why not maintain a runnable signal for the task group se's?
At least to figure out if the 118 is coming from blocked load.
-- >8 --
Subject: [PATCH] sched: Maintain a runnable version of tg->load_avg and
cfs_rq->tg_load_contrib
Including blocked load in the load average contribution of sched
entities (se->avg.load_avg_contrib) representing task groups can
lead to scenarios where the imbalance is greater than
sum(task_h_load(p)) for all tasks p on the src rq.
To avoid this use cfs_rq->runnable_tg_load_contrib and
tg->runnable_load_avg to calculate se->avg.load_avg_contrib for
sched entities representing task groups.
Both runnable based values are updated in cadence with the
existing values.
The existing tg->load_avg and cfs_rq->tg_load_contrib are still
used to calculate task group weight.
Signed-off-by: Dietmar Eggemann <dietmar.eggem...@arm.com>
---
kernel/sched/fair.c | 11 ++++++++---
kernel/sched/sched.h | 2 ++
2 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 587a2f67ceb1..f2cfbaaf5700 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2647,7 +2647,7 @@ static inline void __update_cfs_rq_tg_load_contrib(struct
cfs_rq *cfs_rq,
int force_update)
{
struct task_group *tg = cfs_rq->tg;
- long tg_contrib;
+ long tg_contrib, runnable_tg_contrib;
tg_contrib = cfs_rq->runnable_load_avg + cfs_rq->blocked_load_avg;
tg_contrib -= cfs_rq->tg_load_contrib;
@@ -2655,9 +2655,14 @@ static inline void
__update_cfs_rq_tg_load_contrib(struct cfs_rq *cfs_rq,
if (!tg_contrib)
return;
+ runnable_tg_contrib = cfs_rq->runnable_load_avg;
+ runnable_tg_contrib -= cfs_rq->runnable_tg_load_contrib;
+
if (force_update || abs(tg_contrib) > cfs_rq->tg_load_contrib / 8) {
atomic_long_add(tg_contrib, &tg->load_avg);
cfs_rq->tg_load_contrib += tg_contrib;
+ atomic_long_add(runnable_tg_contrib, &tg->runnable_load_avg);
+ cfs_rq->runnable_tg_load_contrib += runnable_tg_contrib;
}
}
@@ -2690,9 +2695,9 @@ static inline void __update_group_entity_contrib(struct
sched_entity *se)
u64 contrib;
- contrib = cfs_rq->tg_load_contrib * tg->shares;
+ contrib = cfs_rq->runnable_tg_load_contrib * tg->shares;
se->avg.load_avg_contrib = div_u64(contrib,
- atomic_long_read(&tg->load_avg) + 1);
+ atomic_long_read(&tg->runnable_load_avg) + 1);
/*
* For group entities we need to compute a correction term in the case
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 84d48790bb6d..eed74e5efe91 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -245,6 +245,7 @@ struct task_group {
#ifdef CONFIG_SMP
atomic_long_t load_avg;
+ atomic_long_t runnable_load_avg;
atomic_t runnable_avg;
#endif
#endif
@@ -386,6 +387,7 @@ struct cfs_rq {
/* Required to track per-cpu representation of a task_group */
u32 tg_runnable_contrib;
unsigned long tg_load_contrib;
+ unsigned long runnable_tg_load_contrib;
/*
* h_load = weight * f(tg)
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
