diff options
Diffstat (limited to 'meta-eas/recipes-kernel/linux/linux-renesas/0063-sched-Disable-energy-unfriendly-nohz-kicks.patch')
| -rw-r--r-- | meta-eas/recipes-kernel/linux/linux-renesas/0063-sched-Disable-energy-unfriendly-nohz-kicks.patch | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/meta-eas/recipes-kernel/linux/linux-renesas/0063-sched-Disable-energy-unfriendly-nohz-kicks.patch b/meta-eas/recipes-kernel/linux/linux-renesas/0063-sched-Disable-energy-unfriendly-nohz-kicks.patch new file mode 100644 index 0000000..8e96e3f --- /dev/null +++ b/meta-eas/recipes-kernel/linux/linux-renesas/0063-sched-Disable-energy-unfriendly-nohz-kicks.patch @@ -0,0 +1,43 @@ +From 64537223eb2a922fd872741df1a82b1bee325f3e Mon Sep 17 00:00:00 2001 +From: Morten Rasmussen <morten.rasmussen@arm.com> +Date: Tue, 3 Feb 2015 13:54:11 +0000 +Subject: [PATCH 63/92] sched: Disable energy-unfriendly nohz kicks + +With energy-aware scheduling enabled nohz_kick_needed() generates many +nohz idle-balance kicks which lead to nothing when multiple tasks get +packed on a single cpu to save energy. This causes unnecessary wake-ups +and hence wastes energy. Make these conditions depend on !energy_aware() +for now until the energy-aware nohz story gets sorted out. + +cc: Ingo Molnar <mingo@redhat.com> +cc: Peter Zijlstra <peterz@infradead.org> +Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com> +(cherry picked from commit a5268e57a1b257dee1ffa9cd9d670ee747a4ec88) +Signed-off-by: Gaku Inami <gaku.inami.xw@bp.renesas.com> +--- + kernel/sched/fair.c | 5 +++-- + 1 file changed, 3 insertions(+), 2 deletions(-) + +diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c +index 360e922..bc347af 100644 +--- a/kernel/sched/fair.c ++++ b/kernel/sched/fair.c +@@ -9150,12 +9150,13 @@ static inline bool nohz_kick_needed(struct rq *rq) + if (time_before(now, nohz.next_balance)) + return false; + +- if (rq->nr_running >= 2) ++ if (rq->nr_running >= 2 && ++ (!energy_aware() || cpu_overutilized(cpu))) + return true; + + rcu_read_lock(); + sds = rcu_dereference(per_cpu(sd_llc_shared, cpu)); +- if (sds) { ++ if (sds && !energy_aware()) { + /* + * XXX: write a coherent comment on why we do this. + * See also: http://lkml.kernel.org/r/20111202010832.602203411@sbsiddha-desk.sc.intel.com +-- +1.9.1 + |