On Thu, 21 May 2009, GeunSik Lim wrote: > > -- > > commit 16d92cb2334b19751db851d221aab814cd9da1af > Author: GeunSik,Lim <leemgs1@xxxxxxxxx> > Date: Thu May 21 14:31:17 2009 +0900 > > ftrace: fix typo in ftrace.txt file. > > Fix typo about chart to map the kernel priority to > user land priorities. > > * About sched_setscheduler(2) > Processes scheduled under SCHED_FIFO or SCHED_RR > can have a (user-space) static priority in the range 1 to 99. > (reference: http://www.kernel.org/doc/man-pages/online/pages/ > man2/sched_setscheduler.2.html) > > * From: Steven Rostedt > 0 to 98 - maps to RT tasks 99 to 1 (SCHED_RR or SCHED_FIFO) > > 99 - maps to internal kernel threads that want to be lower than RT tasks > but higher than SCHED_OTHER tasks. Although I'm not sure if any > kernel thread actually uses this. I'm not even sure how this can be > set, because the internal sched_setscheduler function does not allow > for it. > > 100 to 139 - maps nice levels -20 to 19. These are not set via > sched_setscheduler, but are set via the nice system call. > > 140 - reserved for idle tasks. > > Signed-off-by: GeunSik Lim <geunsik.lim@xxxxxxxxxxx> > > diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt > index fd9a3e6..e362f50 100644 > --- a/Documentation/trace/ftrace.txt > +++ b/Documentation/trace/ftrace.txt > @@ -518,9 +518,18 @@ priority with zero (0) being the highest priority and the nice > values starting at 100 (nice -20). Below is a quick chart to map > the kernel priority to user land priorities. > > - Kernel priority: 0 to 99 ==> user RT priority 99 to 0 > - Kernel priority: 100 to 139 ==> user nice -20 to 19 > - Kernel priority: 140 ==> idle task priority > + Kernel Space User Space > + =============================================================== > + 0(high) to 98(low) user RT priority 99(high) to 1(low) > + with SCHED_RR or SCHED_FIFO > + --------------------------------------------------------------- > + 99 sched_priority is not used in scheduling > + decisions(it must be specified as 0) > + --------------------------------------------------------------- > + 100(high) to 139(low) user nice -20(high) to 19(low) > + --------------------------------------------------------------- > + 140 idle task priority > + --------------------------------------------------------------- > > The task states are: Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx> Thanks, -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
