sched_stat: Update sched_info_queue/dequeue() code comments

Remove some sched_info_queue(), sched_info_dequeue() code comment. We no longer belongs to the era of O(1) and we don't use active or expired array anymore. Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <AANLkTi=REu0WzOp5N=nVT1=ZJ=ZA+MZFV+4CHSJ3Q-Yv@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>

sched_stat: Update sched_info_queue/dequeue() code comments
Remove some sched_info_queue(), sched_info_dequeue() code comment. We no longer belongs to the era of O(1) and we don't use active or expired array anymore. Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <AANLkTi=REu0WzOp5N=nVT1=ZJ=ZA+MZFV+4CHSJ3Q-Yv@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Rakib Mullick · Ingo Molnar
1 parent b2b5ce022a
Showing 1 changed file with 1 additions and 19 deletions Side-by-side Diff
kernel/sched_stats.h
@@ -157,15 +157,7 @@
 }
  
 /*
- * Called when a process is dequeued from the active array and given
- * the cpu.  We should note that with the exception of interactive
- * tasks, the expired queue will become the active queue after the active
- * queue is empty, without explicitly dequeuing and requeuing tasks in the
- * expired queue.  (Interactive tasks may be requeued directly to the
- * active queue, thus delaying tasks in the expired queue from running;
- * see scheduler_tick()).
- *
- * Though we are interested in knowing how long it was from the *first* time a
+ * We are interested in knowing how long it was from the *first* time a
  * task was queued to the time that it finally hit a cpu, we call this routine
  * from dequeue_task() to account for possible rq->clock skew across cpus. The
  * delta taken on each cpu would annul the skew.
@@ -203,16 +195,6 @@
 }
  
 /*
- * Called when a process is queued into either the active or expired
- * array.  The time is noted and later used to determine how long we
- * had to wait for us to reach the cpu.  Since the expired queue will
- * become the active queue after active queue is empty, without dequeuing
- * and requeuing any tasks, we are interested in queuing to either. It
- * is unusual but not impossible for tasks to be dequeued and immediately
- * requeued in the same or another array: this can happen in sched_yield(),
- * set_user_nice(), and even load_balance() as it moves tasks from runqueue
- * to runqueue.
- *
  * This function is only called from enqueue_task(), but also only updates
  * the timestamp if it is already not set.  It's assumed that
  * sched_info_dequeued() will clear that stamp when appropriate.
...	...	@@ -157,15 +157,7 @@
157	157	}
158	158
159	159	/*
160		- * Called when a process is dequeued from the active array and given
161		- * the cpu. We should note that with the exception of interactive
162		- * tasks, the expired queue will become the active queue after the active
163		- * queue is empty, without explicitly dequeuing and requeuing tasks in the
164		- * expired queue. (Interactive tasks may be requeued directly to the
165		- * active queue, thus delaying tasks in the expired queue from running;
166		- * see scheduler_tick()).
167		- *
168		- * Though we are interested in knowing how long it was from the first time a
	160	+ * We are interested in knowing how long it was from the first time a
169	161	* task was queued to the time that it finally hit a cpu, we call this routine
170	162	* from dequeue_task() to account for possible rq->clock skew across cpus. The
171	163	* delta taken on each cpu would annul the skew.
...	...	@@ -203,16 +195,6 @@
203	195	}
204	196
205	197	/*
206		- * Called when a process is queued into either the active or expired
207		- * array. The time is noted and later used to determine how long we
208		- * had to wait for us to reach the cpu. Since the expired queue will
209		- * become the active queue after active queue is empty, without dequeuing
210		- * and requeuing any tasks, we are interested in queuing to either. It
211		- * is unusual but not impossible for tasks to be dequeued and immediately
212		- * requeued in the same or another array: this can happen in sched_yield(),
213		- * set_user_nice(), and even load_balance() as it moves tasks from runqueue
214		- * to runqueue.
215		- *
216	198	* This function is only called from enqueue_task(), but also only updates
217	199	* the timestamp if it is already not set. It's assumed that
218	200	* sched_info_dequeued() will clear that stamp when appropriate.