[PATCH] sched: cleanup task_activated()

The activated flag in task_struct is used to track different sleep types and
its usage is somewhat obfuscated.  Convert the variable to an enum with more
descriptive names without altering the function.

Signed-off-by: Con Kolivas <kernel@kolivas.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 15 insertions, 9 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 6e52e0adff80..f55ce5adac55 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -704,7 +704,7 @@ static int recalc_task_prio(task_t *p, unsigned long long now)
                  * prevent them suddenly becoming cpu hogs and starving
                  * other processes.
                  */
-                if (p->mm && p->activated != -1 &&
+                if (p->mm && p->sleep_type != SLEEP_NONINTERACTIVE &&
                         sleep_time > INTERACTIVE_SLEEP(p)) {
                                 p->sleep_avg = JIFFIES_TO_NS(MAX_SLEEP_AVG -
                                                 DEF_TIMESLICE);
@@ -714,7 +714,7 @@ static int recalc_task_prio(task_t *p, unsigned long long now)
                          * limited in their sleep_avg rise as they
                          * are likely to be waiting on I/O
                          */
-                        if (p->activated == -1 && p->mm) {
+                        if (p->sleep_type == SLEEP_NONINTERACTIVE && p->mm) {
                                 if (p->sleep_avg >= INTERACTIVE_SLEEP(p))
                                         sleep_time = 0;
                                 else if (p->sleep_avg + sleep_time >=
@@ -769,7 +769,7 @@ static void activate_task(task_t *p, runqueue_t *rq, int local)
          * This checks to make sure it's not an uninterruptible task
          * that is now waking up.
          */
-        if (!p->activated) {
+        if (p->sleep_type == SLEEP_NORMAL) {
                 /*
                  * Tasks which were woken up by interrupts (ie. hw events)
                  * are most likely of interactive nature. So we give them
@@ -778,13 +778,13 @@ static void activate_task(task_t *p, runqueue_t *rq, int local)
                  * on a CPU, first time around:
                  */
                 if (in_interrupt())
-                        p->activated = 2;
+                        p->sleep_type = SLEEP_INTERRUPTED;
                 else {
                         /*
                          * Normal first-time wakeups get a credit too for
                          * on-runqueue time, but it will be weighted down:
                          */
-                        p->activated = 1;
+                        p->sleep_type = SLEEP_INTERACTIVE;
                 }
         }
         p->timestamp = now;
@@ -1272,7 +1272,7 @@ out_activate:
                  * Tasks on involuntary sleep don't earn
                  * sleep_avg beyond just interactive state.
                  */
-                p->activated = -1;
+                p->sleep_type = SLEEP_NONINTERACTIVE;
         }
 
         /*
@@ -2875,6 +2875,12 @@ EXPORT_SYMBOL(sub_preempt_count);
 
 #endif
 
+static inline int interactive_sleep(enum sleep_type sleep_type)
+{
+        return (sleep_type == SLEEP_INTERACTIVE ||
+                sleep_type == SLEEP_INTERRUPTED);
+}
+
 /*
  * schedule() is the main scheduler function.
  */
@@ -2998,12 +3004,12 @@ go_idle:
         queue = array->queue + idx;
         next = list_entry(queue->next, task_t, run_list);
 
-        if (!rt_task(next) && next->activated > 0) {
+        if (!rt_task(next) && interactive_sleep(next->sleep_type)) {
                 unsigned long long delta = now - next->timestamp;
                 if (unlikely((long long)(now - next->timestamp) < 0))
                         delta = 0;
 
-                if (next->activated == 1)
+                if (next->sleep_type == SLEEP_INTERACTIVE)
                         delta = delta * (ON_RUNQUEUE_WEIGHT * 128 / 100) / 128;
 
                 array = next->array;
@@ -3016,7 +3022,7 @@ go_idle:
                 } else
                         requeue_task(next, array);
         }
-        next->activated = 0;
+        next->sleep_type = SLEEP_NORMAL;
 switch_tasks:
         if (next == rq->idle)
                 schedstat_inc(rq, sched_goidle);