Messages in this thread Patch in this message | | | From | Yajun Deng <> | Subject | [PATCH] sched/rt: Redefine RR_TIMESLICE to 100 msecs | Date | Wed, 18 Oct 2023 16:17:09 +0800 |
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The RR_TIMESLICE is currently defined as the jiffies corresponding to 100 msecs. And then sysctl_sched_rr_timeslice will convert RR_TIMESLICE to 100 msecs. These are opposite calculations.
There are msecs_to_jiffies and jiffies_to_msecs in sched_rr_handler. These are also opposite calculations.
Redefine RR_TIMESLICE to 100 msecs, only sched_rr_timeslice needs to convert RR_TIMESLICE to jiffies.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev> --- include/linux/sched/rt.h | 2 +- init/init_task.c | 2 +- kernel/sched/rt.c | 12 +++++------- 3 files changed, 7 insertions(+), 9 deletions(-)
diff --git a/include/linux/sched/rt.h b/include/linux/sched/rt.h index b2b9e6eb9683..74f8f456a804 100644 --- a/include/linux/sched/rt.h +++ b/include/linux/sched/rt.h @@ -58,6 +58,6 @@ extern void normalize_rt_tasks(void); * default timeslice is 100 msecs (used only for SCHED_RR tasks). * Timeslices get refilled after they expire. */ -#define RR_TIMESLICE (100 * HZ / 1000) +#define RR_TIMESLICE (100) #endif /* _LINUX_SCHED_RT_H */ diff --git a/init/init_task.c b/init/init_task.c index 5727d42149c3..86619a425342 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -94,7 +94,7 @@ struct task_struct init_task }, .rt = { .run_list = LIST_HEAD_INIT(init_task.rt.run_list), - .time_slice = RR_TIMESLICE, + .time_slice = (RR_TIMESLICE * HZ) / MSEC_PER_SEC, }, .tasks = LIST_HEAD_INIT(init_task.tasks), #ifdef CONFIG_SMP diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 6aaf0a3d6081..7c0e912094a9 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -4,7 +4,7 @@ * policies) */ -int sched_rr_timeslice = RR_TIMESLICE; +int sched_rr_timeslice = (RR_TIMESLICE * HZ) / MSEC_PER_SEC; /* More than 4 hours if BW_SHIFT equals 20. */ static const u64 max_rt_runtime = MAX_BW; @@ -25,7 +25,7 @@ int sysctl_sched_rt_period = 1000000; int sysctl_sched_rt_runtime = 950000; #ifdef CONFIG_SYSCTL -static int sysctl_sched_rr_timeslice = (MSEC_PER_SEC * RR_TIMESLICE) / HZ; +static int sysctl_sched_rr_timeslice = RR_TIMESLICE; static int sched_rt_handler(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos); static int sched_rr_handler(struct ctl_table *table, int write, void *buffer, @@ -3014,12 +3014,10 @@ static int sched_rr_handler(struct ctl_table *table, int write, void *buffer, * Also, writing zero resets the timeslice to default: */ if (!ret && write) { - sched_rr_timeslice = - sysctl_sched_rr_timeslice <= 0 ? RR_TIMESLICE : - msecs_to_jiffies(sysctl_sched_rr_timeslice); - if (sysctl_sched_rr_timeslice <= 0) - sysctl_sched_rr_timeslice = jiffies_to_msecs(RR_TIMESLICE); + sysctl_sched_rr_timeslice = RR_TIMESLICE; + + sched_rr_timeslice = msecs_to_jiffies(sysctl_sched_rr_timeslice); } mutex_unlock(&mutex); -- 2.25.1
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