[PATCH] sched/debug: check p->se.on_rq for 'runnable tasks'

[PATCH] sched/debug: check p->se.on_rq for 'runnable tasks'

[Zhu Yanhai]

From: Zhu Yanhai <gaoyang.zyh@taobao.com>

I can't see why the check was removed by commit b32e86b4. Since it was not
relevant to the subject of the commit, I guess it was just a plain typo.

Signed-off-by: Zhu Yanhai <gaoyang.zyh@taobao.com>
---
 kernel/sched/debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 2a0a999..ee1ca70 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -456,7 +456,7 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
 
 	rcu_read_lock();
 	for_each_process_thread(g, p) {
-		if (task_cpu(p) != rq_cpu)
+		if (!p->se.on_rq || task_cpu(p) != rq_cpu)
 			continue;
 
 		print_task(m, rq, p);
-- 
2.5.5

Re: [PATCH] sched/debug: check p->se.on_rq for 'runnable tasks'

[Peter Zijlstra]

On Thu, Sep 22, 2016 at 05:50:53PM +0800, Zhu Yanhai wrote:
> From: Zhu Yanhai <gaoyang.zyh@taobao.com>
> 
> I can't see why the check was removed by commit b32e86b4. Since it was not
> relevant to the subject of the commit, I guess it was just a plain typo.

No, it was very much on purpose. It shows all tasks now, which is much
more useful if you want to generate pretty pictures from the output.

Its a bit hard to make pretty pictures when tasks disappear all the
time.

Re: [PATCH] sched/debug: check p->se.on_rq for 'runnable tasks'

[Zhu Yanhai]

2016-09-22 18:08 GMT+08:00 Peter Zijlstra <peterz@infradead.org>:
> On Thu, Sep 22, 2016 at 05:50:53PM +0800, Zhu Yanhai wrote:
>> From: Zhu Yanhai <gaoyang.zyh@taobao.com>
>>
>> I can't see why the check was removed by commit b32e86b4. Since it was not
>> relevant to the subject of the commit, I guess it was just a plain typo.
>
> No, it was very much on purpose. It shows all tasks now, which is much
> more useful if you want to generate pretty pictures from the output.
>
> Its a bit hard to make pretty pictures when tasks disappear all the
> time.

I see. Thanks for your quick reply!