Re: [PATCH 1/1 ,v3] ftrace: fix typo in ftrace.txt file

[Steven Rostedt]

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-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/