diff options
| author | Kevin Hilman <khilman@linaro.org> | 2013-12-17 13:23:07 -0800 |
|---|---|---|
| committer | Gary S. Robertson <gary.robertson@linaro.org> | 2015-07-22 16:17:09 -0500 |
| commit | d67da05964003a7f9765b5fc66c1beb88bc62b25 (patch) | |
| tree | 34056039340aa695001860fa936c37a6ce393de1 | |
| parent | 61655b40f050e503b0d7a2720878328fc650746d (diff) | |
sched/nohz: add debugfs control over sched_tick_max_deferment
Allow debugfs override of sched_tick_max_deferment in order to ease
finding/fixing the remaining issues with full nohz.
The value to be written is in jiffies, and -1 means the max deferment
is disabled (scheduler_tick_max_deferment() returns KTIME_MAX.)
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
| -rw-r--r-- | kernel/sched/core.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 1a7868cd2d1b..eba2f4f78690 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2624,6 +2624,8 @@ void scheduler_tick(void) } #ifdef CONFIG_NO_HZ_FULL +static u32 sched_tick_max_deferment = HZ; + /** * scheduler_tick_max_deferment * @@ -2642,13 +2644,25 @@ u64 scheduler_tick_max_deferment(void) struct rq *rq = this_rq(); unsigned long next, now = ACCESS_ONCE(jiffies); - next = rq->last_sched_tick + HZ; + if (sched_tick_max_deferment == -1) + return KTIME_MAX; + + next = rq->last_sched_tick + sched_tick_max_deferment; if (time_before_eq(next, now)) return 0; return jiffies_to_nsecs(next - now); } + +static __init int sched_nohz_full_init_debug(void) +{ + debugfs_create_u32("sched_tick_max_deferment", 0644, NULL, + &sched_tick_max_deferment); + + return 0; +} +late_initcall(sched_nohz_full_init_debug); #endif notrace unsigned long get_parent_ip(unsigned long addr) |