sched/debug: Intruduce task_state_to_char() helper function

Now that we have more than one place to get the task state,
intruduce the task_state_to_char() helper function to save some code.

No functionality changed.

Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <cj.chengjian@huawei.com>
Cc: <huawei.libin@huawei.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1502095463-160172-3-git-send-email-xiexiuqi@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8337e2db0bb2e71473f94c283c5e51639ddd8dc8..c28b182c9833127751d639a8a77aa2d897e12e66 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1229,6 +1229,19 @@ static inline pid_t task_pgrp_nr(struct task_struct *tsk)
        return task_pgrp_nr_ns(tsk, &init_pid_ns);
 }
 
+static inline char task_state_to_char(struct task_struct *task)
+{
+       const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
+       unsigned long state = task->state;
+
+       state = state ? __ffs(state) + 1 : 0;
+
+       /* Make sure the string lines up properly with the number of task states: */
+       BUILD_BUG_ON(sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1);
+
+       return state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?';
+}
+
 /**
  * is_global_init - check if a task structure is init. Since init
  * is free to have sub-threads we need to check tgid.

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6d91c10b18144ba5fb1023847bd412b400d9719e..f9f9948e2470f970bef0fb1117bf960966dad2d1 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5103,24 +5103,17 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
        return retval;
 }
 
-static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
-
 void sched_show_task(struct task_struct *p)
 {
        unsigned long free = 0;
        int ppid;
-       unsigned long state = p->state;
-
-       /* Make sure the string lines up properly with the number of task states: */
-       BUILD_BUG_ON(sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1);
 
        if (!try_get_task_stack(p))
                return;
-       if (state)
-               state = __ffs(state) + 1;
-       printk(KERN_INFO "%-15.15s %c", p->comm,
-               state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
-       if (state == TASK_RUNNING)
+
+       printk(KERN_INFO "%-15.15s %c", p->comm, task_state_to_char(p));
+
+       if (p->state == TASK_RUNNING)
                printk(KERN_CONT "  running task    ");
 #ifdef CONFIG_DEBUG_STACK_USAGE
        free = stack_not_used(p);

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index d8d2ea215b85d3180d9587c4072a811ce4e3fb26..cfd84f79e0755f69de11aa560c58b82b1c42d283 100644 (file)
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -426,14 +426,10 @@ static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
 static void
 print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
 {
-       unsigned long state;
-
-       if (rq->curr == p) {
+       if (rq->curr == p)
                SEQ_printf(m, ">R");
-       } else {
-               state = p->state ? __ffs(p->state) + 1 : 0;
-               SEQ_printf(m, " %c", state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
-       }
+       else
+               SEQ_printf(m, " %c", task_state_to_char(p));
 
        SEQ_printf(m, "%15s %5d %9Ld.%06ld %9Ld %5d ",
                p->comm, task_pid_nr(p),