lkml.org 
[lkml]   [2007]   [Mar]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
Subjectresend: KERNEL BUG: nice level should not affect SCHED_RR timeslice

Apparently the timeslice of the SCHED_RR process varies with nice level
the same way that it does for SCHED_OTHER. So while niceness doesn't
affect the priority of a SCHED_RR task, it does impact how much cpu it gets.

SUSv3 indicates, "Any processes or threads using SCHED_FIFO or SCHED_RR
shall be unaffected by a call to setpriority()."

The code in set_user_nice() has a comment that leads me to believe the
current behaviour is accidental (although I think the "not" in the last
line isn't meant to be there):

/*
* The RT priorities are set via sched_setscheduler(), but we still
* allow the 'normal' nice value to be set - but as expected
* it wont have any effect on scheduling until the task is
* not SCHED_NORMAL/SCHED_BATCH:
*/

It appears that the desired behaviour is to allow setting the nice level
of a realtime task, but to not have it affect anything until (and
unless) it drops that realtime status. Is this correct?

Chris
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-03-06 16:45    [W:0.028 / U:0.116 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site