Re: [BUG] [ tip/sched/core ] System unresponsive after booting

[Peter Zijlstra <peterz@infradead.org>]

On Thu, Jan 16, 2014 at 03:30:34PM +0100, Daniel Lezcano wrote:
> On 01/16/2014 03:25 PM, Peter Zijlstra wrote:
> >On Thu, Jan 16, 2014 at 03:20:20PM +0100, Daniel Lezcano wrote:
> >>Already tested. The last commits do not change the issue described above.
> >
> >Bummer, ok, what version of Ubuntu/rsyslogd are you using? I have a
> >laptop around that should have some recent ubuntu on it, let me go find
> >it.
> 
> It is a Ubuntu 12.04 and rsyslog 5.8.6-1ubuntu8.4

My laptop has 12.10, I've not yet tried to reproduce but while staring
at the code I noticed a difference with the other can_nice() tests.

Could you try the below while I build a pristine tip/master for the
laptop?

---
 kernel/sched/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 0326c06953eb..e4a3f7e3d613 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3298,7 +3298,7 @@ static int __sched_setscheduler(struct task_struct *p,
 	 */
 	if (user && !capable(CAP_SYS_NICE)) {
 		if (fair_policy(policy)) {
-			if (!can_nice(p, attr->sched_nice))
+			if (attr->sched_nice < TASK_NICE(p) && !can_nice(p, attr->sched_nice))
 				return -EPERM;
 		}