diff options
| author | Kevin Hilman <khilman@linaro.org> | 2013-12-17 13:23:07 -0800 |
|---|---|---|
| committer | Viresh Kumar <viresh.kumar@linaro.org> | 2014-09-05 09:52:51 +0530 |
| commit | 05fa05da1962663a5314aa78a9317ec282a43f23 (patch) | |
| tree | c2fc9b211dd39fb5c8b6bfe7e0d519a485aec26f | |
| parent | a8bcaba5c5a3d0d95246a3920235a8fd8d88d2b7 (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 1b20fc0ec4a7..3e632fe4a192 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2457,6 +2457,8 @@ void scheduler_tick(void) } #ifdef CONFIG_NO_HZ_FULL +static u32 sched_tick_max_deferment = HZ; + /** * scheduler_tick_max_deferment * @@ -2475,13 +2477,25 @@ 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) |