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authorRakib Mullick <rakib.mullick@gmail.com>2010-10-24 06:28:47 -0400
committerIngo Molnar <mingo@elte.hu>2010-10-24 07:29:01 -0400
commitd4a6f3c32c39132318454e77d59ab14b06f6eb02 (patch)
treec693c2293b9183df06f5a5891659fe2090425bff /kernel/sched_stats.h
parentb2b5ce022acf5e9f52f7b78c5579994fdde191d4 (diff)
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>
Diffstat (limited to 'kernel/sched_stats.h')
-rw-r--r--kernel/sched_stats.h20
1 files changed, 1 insertions, 19 deletions
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 25c2f962f6f..48ddf431db0 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -157,15 +157,7 @@ static inline void sched_info_reset_dequeued(struct task_struct *t)
157} 157}
158 158
159/* 159/*
160 * Called when a process is dequeued from the active array and given 160 * We are interested in knowing how long it was from the *first* time a
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
169 * task was queued to the time that it finally hit a cpu, we call this routine 161 * task was queued to the time that it finally hit a cpu, we call this routine
170 * from dequeue_task() to account for possible rq->clock skew across cpus. The 162 * from dequeue_task() to account for possible rq->clock skew across cpus. The
171 * delta taken on each cpu would annul the skew. 163 * delta taken on each cpu would annul the skew.
@@ -203,16 +195,6 @@ static void sched_info_arrive(struct task_struct *t)
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 * This function is only called from enqueue_task(), but also only updates 198 * This function is only called from enqueue_task(), but also only updates
217 * the timestamp if it is already not set. It's assumed that 199 * the timestamp if it is already not set. It's assumed that
218 * sched_info_dequeued() will clear that stamp when appropriate. 200 * sched_info_dequeued() will clear that stamp when appropriate.