From: Keith Owens <kaos@ocs.com.au>
Several scheduler macros only read from the task struct, mark them const.
It can generate better code.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/include/linux/sched.h | 10 +++++-----
25-akpm/kernel/exit.c | 6 +++---
25-akpm/kernel/sched.c | 6 +++---
3 files changed, 11 insertions(+), 11 deletions(-)
diff -puN include/linux/sched.h~add-const-to-some-scheduling-functions include/linux/sched.h
--- 25/include/linux/sched.h~add-const-to-some-scheduling-functions 2004-06-01 00:10:14.529352656 -0700
+++ 25-akpm/include/linux/sched.h 2004-06-01 00:10:14.538351288 -0700
@@ -726,9 +726,9 @@ extern void sched_balance_exec(void);
extern void sched_idle_next(void);
extern void set_user_nice(task_t *p, long nice);
-extern int task_prio(task_t *p);
-extern int task_nice(task_t *p);
-extern int task_curr(task_t *p);
+extern int task_prio(const task_t *p);
+extern int task_nice(const task_t *p);
+extern int task_curr(const task_t *p);
extern int idle_cpu(int cpu);
void yield(void);
@@ -955,7 +955,7 @@ extern void wait_task_inactive(task_t *
#define while_each_thread(g, t) \
while ((t = next_thread(t)) != g)
-extern task_t * FASTCALL(next_thread(task_t *p));
+extern task_t * FASTCALL(next_thread(const task_t *p));
#define thread_group_leader(p) (p->pid == p->tgid)
@@ -1097,7 +1097,7 @@ extern void signal_wake_up(struct task_s
*/
#ifdef CONFIG_SMP
-static inline unsigned int task_cpu(struct task_struct *p)
+static inline unsigned int task_cpu(const struct task_struct *p)
{
return p->thread_info->cpu;
}
diff -puN kernel/exit.c~add-const-to-some-scheduling-functions kernel/exit.c
--- 25/kernel/exit.c~add-const-to-some-scheduling-functions 2004-06-01 00:10:14.531352352 -0700
+++ 25-akpm/kernel/exit.c 2004-06-01 00:10:14.539351136 -0700
@@ -826,10 +826,10 @@ asmlinkage long sys_exit(int error_code)
do_exit((error_code&0xff)<<8);
}
-task_t fastcall *next_thread(task_t *p)
+task_t fastcall *next_thread(const task_t *p)
{
- struct pid_link *link = p->pids + PIDTYPE_TGID;
- struct list_head *tmp, *head = &link->pidptr->task_list;
+ const struct pid_link *link = p->pids + PIDTYPE_TGID;
+ const struct list_head *tmp, *head = &link->pidptr->task_list;
#ifdef CONFIG_SMP
if (!p->sighand)
diff -puN kernel/sched.c~add-const-to-some-scheduling-functions kernel/sched.c
--- 25/kernel/sched.c~add-const-to-some-scheduling-functions 2004-06-01 00:10:14.533352048 -0700
+++ 25-akpm/kernel/sched.c 2004-06-01 00:10:14.549349616 -0700
@@ -652,7 +652,7 @@ static inline void resched_task(task_t *
* task_curr - is this task currently executing on a CPU?
* @p: the task in question.
*/
-inline int task_curr(task_t *p)
+inline int task_curr(const task_t *p)
{
return cpu_curr(task_cpu(p)) == p;
}
@@ -2812,7 +2812,7 @@ asmlinkage long sys_nice(int increment)
* RT tasks are offset by -200. Normal tasks are centered
* around 0, value goes from -16 to +15.
*/
-int task_prio(task_t *p)
+int task_prio(const task_t *p)
{
return p->prio - MAX_RT_PRIO;
}
@@ -2821,7 +2821,7 @@ int task_prio(task_t *p)
* task_nice - return the nice value of a given task.
* @p: the task in question.
*/
-int task_nice(task_t *p)
+int task_nice(const task_t *p)
{
return TASK_NICE(p);
}
_