[PATCH] doc: Document the relax_domain_level kernel boot argument

[PATCH] doc: Document the relax_domain_level kernel boot argument

[Paul Jackson]

From: Paul Jackson <pj@sgi.com>

Document the kernel boot parameter: relax_domain_level=.

Signed-off-by: Paul Jackson <pj@sgi.com>

---
 Documentation/cpusets.txt           |    3 +++
 Documentation/kernel-parameters.txt |    4 ++++
 2 files changed, 7 insertions(+)

--- 2.6.26-rc5-mm3.orig/Documentation/cpusets.txt	2008-06-27 06:55:34.000000000 -0700
+++ 2.6.26-rc5-mm3/Documentation/cpusets.txt	2008-06-29 21:49:53.984674621 -0700
@@ -546,6 +546,9 @@ otherwise initial value -1 that indicate
  ( 4  : search nodes in a chunk of node [on NUMA system] )
  ( 5~ : search system wide [on NUMA system])
 
+The system default is 0 (no search).  The system default can be
+changed using the relax_domain_level= boot parameter.
+
 This file is per-cpuset and affect the sched domain where the cpuset
 belongs to.  Therefore if the flag 'sched_load_balance' of a cpuset
 is disabled, then 'sched_relax_domain_level' have no effect since
--- 2.6.26-rc5-mm3.orig/Documentation/kernel-parameters.txt	2008-06-27 06:28:26.000000000 -0700
+++ 2.6.26-rc5-mm3/Documentation/kernel-parameters.txt	2008-06-29 21:51:10.477997208 -0700
@@ -1732,6 +1732,10 @@ and is between 256 and 4096 characters. 
 			Format: <reboot_mode>[,<reboot_mode2>[,...]]
 			See arch/*/kernel/reboot.c or arch/*/kernel/process.c			
 
+	relax_domain_level=
+			[KNL, SMP] Set schedulers default relax_domain_level.
+			See Documentation/cpusets.txt.
+
 	reserve=	[KNL,BUGS] Force the kernel to ignore some iomem area
 
 	reservetop=	[X86-32]

-- 
                          I won't rest till it's the best ...
                          Programmer, Linux Scalability
                          Paul Jackson <pj@sgi.com> 1.650.933.1373

Re: [PATCH] doc: Document the relax_domain_level kernel boot argument

[Li Zefan]

Paul Jackson wrote:
> From: Paul Jackson <pj@sgi.com>
> 
> Document the kernel boot parameter: relax_domain_level=.
> 
> Signed-off-by: Paul Jackson <pj@sgi.com>
> 
> ---
>  Documentation/cpusets.txt           |    3 +++
>  Documentation/kernel-parameters.txt |    4 ++++
>  2 files changed, 7 insertions(+)
> 
> --- 2.6.26-rc5-mm3.orig/Documentation/cpusets.txt	2008-06-27 06:55:34.000000000 -0700
> +++ 2.6.26-rc5-mm3/Documentation/cpusets.txt	2008-06-29 21:49:53.984674621 -0700
> @@ -546,6 +546,9 @@ otherwise initial value -1 that indicate
>   ( 4  : search nodes in a chunk of node [on NUMA system] )
>   ( 5~ : search system wide [on NUMA system])
>  
> +The system default is 0 (no search).  The system default can be
> +changed using the relax_domain_level= boot parameter.
> +
>  This file is per-cpuset and affect the sched domain where the cpuset
>  belongs to.  Therefore if the flag 'sched_load_balance' of a cpuset
>  is disabled, then 'sched_relax_domain_level' have no effect since
> --- 2.6.26-rc5-mm3.orig/Documentation/kernel-parameters.txt	2008-06-27 06:28:26.000000000 -0700
> +++ 2.6.26-rc5-mm3/Documentation/kernel-parameters.txt	2008-06-29 21:51:10.477997208 -0700
> @@ -1732,6 +1732,10 @@ and is between 256 and 4096 characters. 
>  			Format: <reboot_mode>[,<reboot_mode2>[,...]]
>  			See arch/*/kernel/reboot.c or arch/*/kernel/process.c			
>  
> +	relax_domain_level=
> +			[KNL, SMP] Set schedulers default relax_domain_level.
> +			See Documentation/cpusets.txt.
> +

is [KNL,SMP] more consistent ?

and s/schedulers/scheduler's/

but maybe I'm wrong due to my English skill.

>  	reserve=	[KNL,BUGS] Force the kernel to ignore some iomem area
>  
>  	reservetop=	[X86-32]
> 

Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>

Re: [PATCH] doc: Document the relax_domain_level kernel boot argument

[Hidetoshi Seto]

Hi Paul,

Paul Jackson wrote:
> From: Paul Jackson <pj@sgi.com>
> 
> Document the kernel boot parameter: relax_domain_level=.
> 
> Signed-off-by: Paul Jackson <pj@sgi.com>
> 
> ---
>  Documentation/cpusets.txt           |    3 +++
>  Documentation/kernel-parameters.txt |    4 ++++
>  2 files changed, 7 insertions(+)
> 
> --- 2.6.26-rc5-mm3.orig/Documentation/cpusets.txt	2008-06-27 06:55:34.000000000 -0700
> +++ 2.6.26-rc5-mm3/Documentation/cpusets.txt	2008-06-29 21:49:53.984674621 -0700
> @@ -546,6 +546,9 @@ otherwise initial value -1 that indicate
>   ( 4  : search nodes in a chunk of node [on NUMA system] )
>   ( 5~ : search system wide [on NUMA system])
>  
> +The system default is 0 (no search).  The system default can be
> +changed using the relax_domain_level= boot parameter.

The system default is architecture dependent. You can change your
system's default using the relax_domain_level= boot parameter.

Thanks,
H.Seto

Re: [PATCH] doc: Document the relax_domain_level kernel boot argument

[Michael Kerrisk]

On Mon, Jun 30, 2008 at 8:08 AM, Li Zefan <lizf@cn.fujitsu.com> wrote:
> Paul Jackson wrote:
>> From: Paul Jackson <pj@sgi.com>
>>
>> Document the kernel boot parameter: relax_domain_level=.
>>
>> Signed-off-by: Paul Jackson <pj@sgi.com>
>>
>> ---
>>  Documentation/cpusets.txt           |    3 +++
>>  Documentation/kernel-parameters.txt |    4 ++++
>>  2 files changed, 7 insertions(+)
>>
>> --- 2.6.26-rc5-mm3.orig/Documentation/cpusets.txt     2008-06-27 06:55:34.000000000 -0700
>> +++ 2.6.26-rc5-mm3/Documentation/cpusets.txt  2008-06-29 21:49:53.984674621 -0700
>> @@ -546,6 +546,9 @@ otherwise initial value -1 that indicate
>>   ( 4  : search nodes in a chunk of node [on NUMA system] )
>>   ( 5~ : search system wide [on NUMA system])
>>
>> +The system default is 0 (no search).  The system default can be
>> +changed using the relax_domain_level= boot parameter.
>> +
>>  This file is per-cpuset and affect the sched domain where the cpuset
>>  belongs to.  Therefore if the flag 'sched_load_balance' of a cpuset
>>  is disabled, then 'sched_relax_domain_level' have no effect since
>> --- 2.6.26-rc5-mm3.orig/Documentation/kernel-parameters.txt   2008-06-27 06:28:26.000000000 -0700
>> +++ 2.6.26-rc5-mm3/Documentation/kernel-parameters.txt        2008-06-29 21:51:10.477997208 -0700
>> @@ -1732,6 +1732,10 @@ and is between 256 and 4096 characters.
>>                       Format: <reboot_mode>[,<reboot_mode2>[,...]]
>>                       See arch/*/kernel/reboot.c or arch/*/kernel/process.c
>>
>> +     relax_domain_level=
>> +                     [KNL, SMP] Set schedulers default relax_domain_level.
>> +                     See Documentation/cpusets.txt.
>> +
>
> is [KNL,SMP] more consistent ?
>
> and s/schedulers/scheduler's/
>
> but maybe I'm wrong due to my English skill.

You are right.  (Paul doesn't like apostrophes ;-).)

>>       reserve=        [KNL,BUGS] Force the kernel to ignore some iomem area
>>
>>       reservetop=     [X86-32]
>>
>
> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
>
>



-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
man-pages online: http://www.kernel.org/doc/man-pages/online_pages.html
Found a bug? http://www.kernel.org/doc/man-pages/reporting_bugs.html

Re: [PATCH] doc: Document the relax_domain_level kernel boot argument

[Li Zefan]

Hidetoshi Seto wrote:
> Hi Paul,
> 
> Paul Jackson wrote:
>> From: Paul Jackson <pj@sgi.com>
>>
>> Document the kernel boot parameter: relax_domain_level=.
>>
>> Signed-off-by: Paul Jackson <pj@sgi.com>
>>
>> ---
>>  Documentation/cpusets.txt           |    3 +++
>>  Documentation/kernel-parameters.txt |    4 ++++
>>  2 files changed, 7 insertions(+)
>>
>> --- 2.6.26-rc5-mm3.orig/Documentation/cpusets.txt	2008-06-27 06:55:34.000000000 -0700
>> +++ 2.6.26-rc5-mm3/Documentation/cpusets.txt	2008-06-29 21:49:53.984674621 -0700
>> @@ -546,6 +546,9 @@ otherwise initial value -1 that indicate
>>   ( 4  : search nodes in a chunk of node [on NUMA system] )
>>   ( 5~ : search system wide [on NUMA system])
>>  
>> +The system default is 0 (no search).  The system default can be
>> +changed using the relax_domain_level= boot parameter.
> 
> The system default is architecture dependent. You can change your
> system's default using the relax_domain_level= boot parameter.
> 

but the system default is 0 by default. and 0 means no search no matter
what architecture is. ;)

> Thanks,
> H.Seto
> 
> 

Re: [PATCH] doc: Document the relax_domain_level kernel boot argument

[Hidetoshi Seto]

Li Zefan wrote:
> Hidetoshi Seto wrote:
>> The system default is architecture dependent. You can change your
>> system's default using the relax_domain_level= boot parameter.
> 
> but the system default is 0 by default. and 0 means no search no matter
> what architecture is. ;)

If my git pull works correctly, it seems that the default is still -1...

[kernel/sched.c]
> static int default_relax_domain_level = -1;

AFAIK, for example, x86(SMT) search siblings by default.

Thanks,
H.Seto

Re: [PATCH] doc: Document the relax_domain_level kernel boot argument

[Li Zefan]

Hidetoshi Seto wrote:
> Li Zefan wrote:
>> Hidetoshi Seto wrote:
>>> The system default is architecture dependent. You can change your
>>> system's default using the relax_domain_level= boot parameter.
>> but the system default is 0 by default. and 0 means no search no matter
>> what architecture is. ;)
> 
> If my git pull works correctly, it seems that the default is still -1...
> 

Ah, yes, it's my mistake. :(

> [kernel/sched.c]
>> static int default_relax_domain_level = -1;
> 
> AFAIK, for example, x86(SMT) search siblings by default.
> 

So the system default is architecture depentdent.

> Thanks,
> H.Seto
> 
> 

Re: [PATCH] doc: Document the relax_domain_level kernel boot argument

[Paul Jackson]

Michael wrote:
> Paul doesn't like apostrophes ;-)

You got that right -- I hate them ;).

-- 
                  I won't rest till it's the best ...
                  Programmer, Linux Scalability
                  Paul Jackson <pj@sgi.com> 1.940.382.4214