diff options
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 41 |
1 files changed, 17 insertions, 24 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index ce9bb7aa7c1..f370f108ed0 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -96,7 +96,7 @@ unsigned long long __attribute__((weak)) sched_clock(void) /* * Some helpers for converting nanosecond timing to jiffy resolution */ -#define NS_TO_JIFFIES(TIME) ((TIME) / (1000000000 / HZ)) +#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (1000000000 / HZ)) #define JIFFIES_TO_NS(TIME) ((TIME) * (1000000000 / HZ)) #define NICE_0_LOAD SCHED_LOAD_SCALE @@ -105,11 +105,9 @@ unsigned long long __attribute__((weak)) sched_clock(void) /* * These are the 'tuning knobs' of the scheduler: * - * Minimum timeslice is 5 msecs (or 1 jiffy, whichever is larger), - * default timeslice is 100 msecs, maximum timeslice is 800 msecs. + * default timeslice is 100 msecs (used only for SCHED_RR tasks). * Timeslices get refilled after they expire. */ -#define MIN_TIMESLICE max(5 * HZ / 1000, 1) #define DEF_TIMESLICE (100 * HZ / 1000) #ifdef CONFIG_SMP @@ -133,24 +131,6 @@ static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val) } #endif -#define SCALE_PRIO(x, prio) \ - max(x * (MAX_PRIO - prio) / (MAX_USER_PRIO / 2), MIN_TIMESLICE) - -/* - * static_prio_timeslice() scales user-nice values [ -20 ... 0 ... 19 ] - * to time slice values: [800ms ... 100ms ... 5ms] - */ -static unsigned int static_prio_timeslice(int static_prio) -{ - if (static_prio == NICE_TO_PRIO(19)) - return 1; - - if (static_prio < NICE_TO_PRIO(0)) - return SCALE_PRIO(DEF_TIMESLICE * 4, static_prio); - else - return SCALE_PRIO(DEF_TIMESLICE, static_prio); -} - static inline int rt_policy(int policy) { if (unlikely(policy == SCHED_FIFO) || unlikely(policy == SCHED_RR)) @@ -4746,6 +4726,7 @@ asmlinkage long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval) { struct task_struct *p; + unsigned int time_slice; int retval = -EINVAL; struct timespec t; @@ -4762,9 +4743,21 @@ long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval) if (retval) goto out_unlock; - jiffies_to_timespec(p->policy == SCHED_FIFO ? - 0 : static_prio_timeslice(p->static_prio), &t); + if (p->policy == SCHED_FIFO) + time_slice = 0; + else if (p->policy == SCHED_RR) + time_slice = DEF_TIMESLICE; + else { + struct sched_entity *se = &p->se; + unsigned long flags; + struct rq *rq; + + rq = task_rq_lock(p, &flags); + time_slice = NS_TO_JIFFIES(sched_slice(cfs_rq_of(se), se)); + task_rq_unlock(rq, &flags); + } read_unlock(&tasklist_lock); + jiffies_to_timespec(time_slice, &t); retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; out_nounlock: return retval; |