diff options
| author | Clark Williams <williams@redhat.com> | 2013-02-07 09:47:04 -0600 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-02-07 20:51:07 +0100 |
| commit | ce0dbbbb30aee6a835511d5be446462388ba9eee (patch) | |
| tree | c3d4d6f64a0fe7eec9283f4413d111a8d37d7053 /kernel | |
| parent | cf4aebc292fac7f34f8345664320e9d4a42ca76c (diff) | |
sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice
Add a /proc/sys/kernel scheduler knob named
sched_rr_timeslice_ms that allows global changing of the
SCHED_RR timeslice value. User visable value is in milliseconds
but is stored as jiffies. Setting to 0 (zero) resets to the
default (currently 100ms).
Signed-off-by: Clark Williams <williams@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20130207094704.13751796@riff.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/core.c | 19 | ||||
| -rw-r--r-- | kernel/sched/rt.c | 6 | ||||
| -rw-r--r-- | kernel/sysctl.c | 7 |
3 files changed, 30 insertions, 2 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 1dff78a9e2ab..4a88f1d51563 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7509,6 +7509,25 @@ static int sched_rt_global_constraints(void) } #endif /* CONFIG_RT_GROUP_SCHED */ +int sched_rr_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos) +{ + int ret; + static DEFINE_MUTEX(mutex); + + mutex_lock(&mutex); + ret = proc_dointvec(table, write, buffer, lenp, ppos); + /* make sure that internally we keep jiffies */ + /* also, writing zero resets timeslice to default */ + if (!ret && write) { + sched_rr_timeslice = sched_rr_timeslice <= 0 ? + RR_TIMESLICE : msecs_to_jiffies(sched_rr_timeslice); + } + mutex_unlock(&mutex); + return ret; +} + int sched_rt_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index c25de141c576..fb0f77e402b6 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -7,6 +7,8 @@ #include <linux/slab.h> +int sched_rr_timeslice = RR_TIMESLICE; + static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); struct rt_bandwidth def_rt_bandwidth; @@ -2016,7 +2018,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) if (--p->rt.time_slice) return; - p->rt.time_slice = RR_TIMESLICE; + p->rt.time_slice = sched_rr_timeslice; /* * Requeue to the end of queue if we (and all of our ancestors) are the @@ -2047,7 +2049,7 @@ static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task) * Time slice is 0 for SCHED_FIFO tasks */ if (task->policy == SCHED_RR) - return RR_TIMESLICE; + return sched_rr_timeslice; else return 0; } diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 7357e23aaf68..4fc9be955c71 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -404,6 +404,13 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = sched_rt_handler, }, + { + .procname = "sched_rr_timeslice_ms", + .data = &sched_rr_timeslice, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = sched_rr_handler, + }, #ifdef CONFIG_SCHED_AUTOGROUP { .procname = "sched_autogroup_enabled", |