From: Dongsheng Yang Date: Tue, 28 Jan 2014 03:00:45 +0000 (-0500) Subject: sched: Implement task_nice() as static inline function X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d0ea026808ad81de2af14938448419a95211b938;p=linux-beck.git sched: Implement task_nice() as static inline function As patch "sched: Move the priority specific bits into a new header file" exposes the priority related macros in linux/sched/prio.h, we don't have to implement task_nice() in kernel/sched/core.c any more. This patch implements it in linux/sched/sched.h as static inline function, saving the kernel stack and enhancing performance a bit. Signed-off-by: Dongsheng Yang Cc: clark.williams@gmail.com Cc: rostedt@goodmis.org Cc: raistlin@linux.it Cc: juri.lelli@gmail.com Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1390878045-7096-1-git-send-email-yangds.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar --- diff --git a/include/linux/sched.h b/include/linux/sched.h index d97d0a8e87dc..e3d556427b2e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2094,7 +2094,16 @@ static inline void sched_autogroup_exit(struct signal_struct *sig) { } extern bool yield_to(struct task_struct *p, bool preempt); extern void set_user_nice(struct task_struct *p, long nice); extern int task_prio(const struct task_struct *p); -extern int task_nice(const struct task_struct *p); +/** + * task_nice - return the nice value of a given task. + * @p: the task in question. + * + * Return: The nice value [ -20 ... 0 ... 19 ]. + */ +static inline int task_nice(const struct task_struct *p) +{ + return PRIO_TO_NICE((p)->static_prio); +} extern int can_nice(const struct task_struct *p, const int nice); extern int task_curr(const struct task_struct *p); extern int idle_cpu(int cpu); diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h index 13216f16762e..410ccb74c9e6 100644 --- a/include/linux/sched/prio.h +++ b/include/linux/sched/prio.h @@ -27,7 +27,6 @@ */ #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) -#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) /* * 'User priority' is the nice value converted to something we diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 210a12acf2cd..104c8164e04f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3000,7 +3000,7 @@ void set_user_nice(struct task_struct *p, long nice) unsigned long flags; struct rq *rq; - if (TASK_NICE(p) == nice || nice < -20 || nice > 19) + if (task_nice(p) == nice || nice < -20 || nice > 19) return; /* * We have to be careful, if called from sys_setpriority(), @@ -3078,7 +3078,7 @@ SYSCALL_DEFINE1(nice, int, increment) if (increment > 40) increment = 40; - nice = TASK_NICE(current) + increment; + nice = task_nice(current) + increment; if (nice < -20) nice = -20; if (nice > 19) @@ -3110,18 +3110,6 @@ int task_prio(const struct task_struct *p) return p->prio - MAX_RT_PRIO; } -/** - * task_nice - return the nice value of a given task. - * @p: the task in question. - * - * Return: The nice value [ -20 ... 0 ... 19 ]. - */ -int task_nice(const struct task_struct *p) -{ - return TASK_NICE(p); -} -EXPORT_SYMBOL(task_nice); - /** * idle_cpu - is a given cpu idle currently? * @cpu: the processor in question. @@ -3321,7 +3309,7 @@ recheck: */ if (user && !capable(CAP_SYS_NICE)) { if (fair_policy(policy)) { - if (attr->sched_nice < TASK_NICE(p) && + if (attr->sched_nice < task_nice(p) && !can_nice(p, attr->sched_nice)) return -EPERM; } @@ -3345,7 +3333,7 @@ recheck: * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. */ if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) { - if (!can_nice(p, TASK_NICE(p))) + if (!can_nice(p, task_nice(p))) return -EPERM; } @@ -3385,7 +3373,7 @@ recheck: * If not changing anything there's no need to proceed further: */ if (unlikely(policy == p->policy)) { - if (fair_policy(policy) && attr->sched_nice != TASK_NICE(p)) + if (fair_policy(policy) && attr->sched_nice != task_nice(p)) goto change; if (rt_policy(policy) && attr->sched_priority != p->rt_priority) goto change; @@ -3837,7 +3825,7 @@ SYSCALL_DEFINE3(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, else if (task_has_rt_policy(p)) attr.sched_priority = p->rt_priority; else - attr.sched_nice = TASK_NICE(p); + attr.sched_nice = task_nice(p); rcu_read_unlock(); @@ -7010,7 +6998,7 @@ void normalize_rt_tasks(void) * Renice negative nice level userspace * tasks back to 0: */ - if (TASK_NICE(p) < 0 && p->mm) + if (task_nice(p) < 0 && p->mm) set_user_nice(p, 0); continue; } diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 99947919e30b..58624a65f124 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -142,7 +142,7 @@ void account_user_time(struct task_struct *p, cputime_t cputime, p->utimescaled += cputime_scaled; account_group_user_time(p, cputime); - index = (TASK_NICE(p) > 0) ? CPUTIME_NICE : CPUTIME_USER; + index = (task_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER; /* Add user time to cpustat. */ task_group_account_field(p, index, (__force u64) cputime); @@ -169,7 +169,7 @@ static void account_guest_time(struct task_struct *p, cputime_t cputime, p->gtime += cputime; /* Add guest time to cpustat. */ - if (TASK_NICE(p) > 0) { + if (task_nice(p) > 0) { cpustat[CPUTIME_NICE] += (__force u64) cputime; cpustat[CPUTIME_GUEST_NICE] += (__force u64) cputime; } else {