sched/rt: Show the 'sched_rr_timeslice' SCHED_RR timeslice tuning knob in milliseconds

We added the 'sched_rr_timeslice_ms' SCHED_RR tuning knob in this commit: ce0dbbbb30ae ("sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice") ... which name suggests to users that it's in milliseconds, while in reality it's being set in milliseconds but the result is shown in jiffies. This is obviously confusing when HZ is not 1000, it makes it appear like the value set failed, such as HZ=100: root# echo 100 > /proc/sys/kernel/sched_rr_timeslice_ms root# cat /proc/sys/kernel/sched_rr_timeslice_ms 10 Fix this to be milliseconds all around.

Shile Zhang committed 9 years ago

Commit 975e1551 parent 733ce724 files · +6 −3Browse files

Unified · Split

4 files

include/linux/sched/sysctl.h +1 −0
kernel/sched/core.c +3 −2
kernel/sched/rt.c +1 −0
kernel/sysctl.c +1 −1

include/linux/sched/sysctl.h+1−0

@@ -59,6 +59,7 @@ extern unsigned int sysctl_sched_cfs_bandwidth_slice; · 58 unmodified lines
59	59	extern unsigned int sysctl_sched_autogroup_enabled;
60	60	#endif
61	61
	62	+extern int sysctl_sched_rr_timeslice;
62	63	extern int sched_rr_timeslice;
63	64
64	65	extern int sched_rr_handler(struct ctl_table *table, int write,

kernel/sched/core.c+3−2

@@ -8471,8 +8471,9 @@ int sched_rr_handler(struct ctl_table *table, int write, · 8470 unmodified lines
8471	8471	/* make sure that internally we keep jiffies */
8472	8472	/* also, writing zero resets timeslice to default */
8473	8473	if (!ret && write) {
8474		− sched_rr_timeslice = sched_rr_timeslice <= 0 ?
8475		− RR_TIMESLICE : msecs_to_jiffies(sched_rr_timeslice);
	8474	+ sched_rr_timeslice =
	8475	+ sysctl_sched_rr_timeslice <= 0 ? RR_TIMESLICE :
	8476	+ msecs_to_jiffies(sysctl_sched_rr_timeslice);
8476	8477	}
8477	8478	mutex_unlock(&mutex);
8478	8479	return ret;

kernel/sched/rt.c+1−0

@@ -9,6 +9,7 @@ · 8 unmodified lines
9	9	#include <linux/irq_work.h>
10	10
11	11	int sched_rr_timeslice = RR_TIMESLICE;
	12	+int sysctl_sched_rr_timeslice = (MSEC_PER_SEC / HZ) * RR_TIMESLICE;
12	13
13	14	static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);
14	15

kernel/sysctl.c+1−1

@@ -416,7 +416,7 @@ static struct ctl_table kern_table[] = { · 415 unmodified lines
416	416	},
417	417	{
418	418	.procname = "sched_rr_timeslice_ms",
419		− .data = &sched_rr_timeslice,
	419	+ .data = &sysctl_sched_rr_timeslice,
420	420	.maxlen = sizeof(int),
421	421	.mode = 0644,
422	422	.proc_handler = sched_rr_handler,