[PATCH]sched: fix typo in sched-rt-group.txt file

[PATCH]sched: fix typo in sched-rt-group.txt file

[GeunSik Lim]

[-- Attachment #1: Type: text/plain, Size: 1868 bytes --]




Dear Ingo,

I found typo about the range of static priority ( = realtime priority )
in "./Documentation/scheduler/sched-rt-group.txt" file.

If I don't understand static priority levels, Correct me.


commit d6af702008117ca489a2f5476239d1688a517e98
Author: GeunSik,Lim <leemgs1@gmail.com>
Date:   Tue May 12 17:20:32 2009 +0900

    sched: fix typo in sched-rt-group.txt file
    
    Fix typo about static priority's range.
     Kernel Space priority: 0   to 99   --> User Space RT priority 99 to 0
     Kernel Space priority: 100 to 139  --> User Space nice -20 to 19
    
    Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com>

diff --git a/Documentation/scheduler/sched-rt-group.txt b/Documentation/scheduler/sched-rt-group.txt
index 5ba4d3f..1537146 100644
--- a/Documentation/scheduler/sched-rt-group.txt
+++ b/Documentation/scheduler/sched-rt-group.txt
@@ -169,7 +169,7 @@ get their allocated time.
 
 Implementing SCHED_EDF might take a while to complete. Priority Inheritance is
 the biggest challenge as the current linux PI infrastructure is geared towards
-the limited static priority levels 0-139. With deadline scheduling you need to
+the limited static priority levels 0-99. With deadline scheduling you need to
 do deadline inheritance (since priority is inversely proportional to the
 deadline delta (deadline - now).
 


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GeunSik Lim (ELS - OS Group - S/W Lab - SAIT - SAMSUNG)
e-Mail  :1) geunsik.lim@samsung.com
         2) leemgs@gmail.com , leemgs1@gmail.com
HomePage: http://intomail.dnip.net/invain/me/
-----------------------------------------------

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commit d6af702008117ca489a2f5476239d1688a517e98
Author: GeunSik,Lim <leemgs1@gmail.com>
Date:   Tue May 12 17:20:32 2009 +0900

    sched: fix typo in sched-rt-group.txt file
    
    Fix typo about static priority's range.
     Kernel Space priority: 0   to 99   --> User Space RT priority 99 to 0
     Kernel Space priority: 100 to 139  --> User Space nice -20 to 19
    
    Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com>

diff --git a/Documentation/scheduler/sched-rt-group.txt b/Documentation/scheduler/sched-rt-group.txt
index 5ba4d3f..1537146 100644
--- a/Documentation/scheduler/sched-rt-group.txt
+++ b/Documentation/scheduler/sched-rt-group.txt
@@ -169,7 +169,7 @@ get their allocated time.
 
 Implementing SCHED_EDF might take a while to complete. Priority Inheritance is
 the biggest challenge as the current linux PI infrastructure is geared towards
-the limited static priority levels 0-139. With deadline scheduling you need to
+the limited static priority levels 0-99. With deadline scheduling you need to
 do deadline inheritance (since priority is inversely proportional to the
 deadline delta (deadline - now).
 

Re: [PATCH]sched: fix typo in sched-rt-group.txt file

[Peter Zijlstra]

On Tue, 2009-05-12 at 17:37 +0900, GeunSik Lim wrote:
> 
> 
> Dear Ingo,
> 
> I found typo about the range of static priority ( = realtime priority )
> in "./Documentation/scheduler/sched-rt-group.txt" file.
> 
> If I don't understand static priority levels, Correct me.

Right, that 'confusion' stems from the fact that our in-kernel priority
lists do consider all 140 priorities.

The patch looks good though.

> commit d6af702008117ca489a2f5476239d1688a517e98
> Author: GeunSik,Lim <leemgs1@gmail.com>
> Date:   Tue May 12 17:20:32 2009 +0900
> 
>     sched: fix typo in sched-rt-group.txt file
>     
>     Fix typo about static priority's range.
>      Kernel Space priority: 0   to 99   --> User Space RT priority 99 to 0
>      Kernel Space priority: 100 to 139  --> User Space nice -20 to 19
>     
>     Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com>
> 
> diff --git a/Documentation/scheduler/sched-rt-group.txt b/Documentation/scheduler/sched-rt-group.txt
> index 5ba4d3f..1537146 100644
> --- a/Documentation/scheduler/sched-rt-group.txt
> +++ b/Documentation/scheduler/sched-rt-group.txt
> @@ -169,7 +169,7 @@ get their allocated time.
>  
>  Implementing SCHED_EDF might take a while to complete. Priority Inheritance is
>  the biggest challenge as the current linux PI infrastructure is geared towards
> -the limited static priority levels 0-139. With deadline scheduling you need to
> +the limited static priority levels 0-99. With deadline scheduling you need to
>  do deadline inheritance (since priority is inversely proportional to the
>  deadline delta (deadline - now).
>  
> 
> 
> -----------------------------------------------
> To unsubscribe from this list: send the line "unsubscribe linux-***" 
> 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/
> 
> GeunSik Lim (ELS - OS Group - S/W Lab - SAIT - SAMSUNG)
> e-Mail  :1) geunsik.lim@samsung.com
>          2) leemgs@gmail.com , leemgs1@gmail.com
> HomePage: http://intomail.dnip.net/invain/me/
> -----------------------------------------------

Re: [PATCH]sched: fix typo in sched-rt-group.txt file

[Ingo Molnar]

* Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:

> On Tue, 2009-05-12 at 17:37 +0900, GeunSik Lim wrote:
> > 
> > 
> > Dear Ingo,
> > 
> > I found typo about the range of static priority ( = realtime priority )
> > in "./Documentation/scheduler/sched-rt-group.txt" file.
> > 
> > If I don't understand static priority levels, Correct me.
> 
> Right, that 'confusion' stems from the fact that our in-kernel priority
> lists do consider all 140 priorities.
> 
> The patch looks good though.
> 
> > commit d6af702008117ca489a2f5476239d1688a517e98
> > Author: GeunSik,Lim <leemgs1@gmail.com>
> > Date:   Tue May 12 17:20:32 2009 +0900
> > 
> >     sched: fix typo in sched-rt-group.txt file
> >     
> >     Fix typo about static priority's range.
> >      Kernel Space priority: 0   to 99   --> User Space RT priority 99 to 0
> >      Kernel Space priority: 100 to 139  --> User Space nice -20 to 19
> >     
> >     Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com>
> > 
> > diff --git a/Documentation/scheduler/sched-rt-group.txt b/Documentation/scheduler/sched-rt-group.txt
> > index 5ba4d3f..1537146 100644
> > --- a/Documentation/scheduler/sched-rt-group.txt
> > +++ b/Documentation/scheduler/sched-rt-group.txt
> > @@ -169,7 +169,7 @@ get their allocated time.
> >  
> >  Implementing SCHED_EDF might take a while to complete. Priority Inheritance is
> >  the biggest challenge as the current linux PI infrastructure is geared towards
> > -the limited static priority levels 0-139. With deadline scheduling you need to
> > +the limited static priority levels 0-99. With deadline scheduling you need to

SCHED_FIFO goes from 1 to 99. So it's either 0-98 or 1-99. From 
sched_setscheduler(2):

       Processes scheduled under one of  the  real-time  policies  (SCHED_FIFO,
       SCHED_RR) have a sched_priority value in the range 1 (low) to 99 (high).

	Ingo

Re: [PATCH]sched: fix typo in sched-rt-group.txt file

[GeunSik Lim]

2009/5/12 Ingo Molnar <mingo@elte.hu>:
>
> * Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
>
>> On Tue, 2009-05-12 at 17:37 +0900, GeunSik Lim wrote:
>> >
>> >
>> > Dear Ingo,
>> >
>> > I found typo about the range of static priority ( = realtime priority )
>> > in "./Documentation/scheduler/sched-rt-group.txt" file.
>> >
>> > If I don't understand static priority levels, Correct me.
>>
>> Right, that 'confusion' stems from the fact that our in-kernel priority
>> lists do consider all 140 priorities.
>>
>> The patch looks good though.
>>
>> > commit d6af702008117ca489a2f5476239d1688a517e98
>> > Author: GeunSik,Lim <leemgs1@gmail.com>
>> > Date:   Tue May 12 17:20:32 2009 +0900
>> >
>> >     sched: fix typo in sched-rt-group.txt file
>> >
>> >     Fix typo about static priority's range.
>> >      Kernel Space priority: 0   to 99   --> User Space RT priority 99 to 0
>> >      Kernel Space priority: 100 to 139  --> User Space nice -20 to 19
>> >
>> >     Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com>
>> >
>> > diff --git a/Documentation/scheduler/sched-rt-group.txt b/Documentation/scheduler/sched-rt-group.txt
>> > index 5ba4d3f..1537146 100644
>> > --- a/Documentation/scheduler/sched-rt-group.txt
>> > +++ b/Documentation/scheduler/sched-rt-group.txt
>> > @@ -169,7 +169,7 @@ get their allocated time.
>> >
>> >  Implementing SCHED_EDF might take a while to complete. Priority Inheritance is
>> >  the biggest challenge as the current linux PI infrastructure is geared towards
>> > -the limited static priority levels 0-139. With deadline scheduling you need to
>> > +the limited static priority levels 0-99. With deadline scheduling you need to
>
> SCHED_FIFO goes from 1 to 99. So it's either 0-98 or 1-99. From
> sched_setscheduler(2):
>
>       Processes scheduled under one of  the  real-time  policies  (SCHED_FIFO,
>       SCHED_RR) have a sched_priority value in the range 1 (low) to 99 (high).
>
>        Ingo
>

Thank you for explanation about userspace rt priority's range like
sched_setscheduler(2).

Processes scheduled with SCHED_OTHER (or SCHED_BATCH) must be assigned
the static priority 0.  Processes scheduled under SCHED_FIFO (or
SCHED_RR) can have a static priority in the range 1 to 99.

So, I think that the below summary is right.
* Kernel Space priority: 0(high) to 99(low) --> User Space RT priority
99(high) to 0(low)

Is it incorrect?


-- 
Regards,
GeunSik Lim
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