cpusets: document adding/removing cpus to cpuset elaborately

cpusets: document adding/removing cpus to cpuset elaborately

[Nikanth Karthikesan]

Writing a pid to the file, tasks adds that task to that cgroup/cpuset. But to
add a cpu/mem to a cpuset, the new list of cpus should be written to the
cpuset.mems file which would replace the old list of cpus. Make this clearer
in the documentation.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>

---

diff --git a/Documentation/cgroups/cpusets.txt b/Documentation/cgroups/cpusets.txt
index f9ca389..1d7e978 100644
--- a/Documentation/cgroups/cpusets.txt
+++ b/Documentation/cgroups/cpusets.txt
@@ -777,6 +777,18 @@ in cpuset directories:
 # /bin/echo 1-4 > cpus		-> set cpus list to cpus 1,2,3,4
 # /bin/echo 1,2,3,4 > cpus	-> set cpus list to cpus 1,2,3,4
 
+To add a CPU to a cpuset, write the new list of CPUs including the
+CPU to be added. To add 6 to the above cpuset:
+
+# /bin/echo 1-4,6 > cpus	-> set cpus list to cpus 1,2,3,4,6
+
+Similarly to remove a CPU from a cpuset, write the new list of CPUs
+without the CPU to be removed.
+
+To remove all the CPUs:
+
+# /bin/echo "" > cpus		-> clear cpus list
+
 2.3 Setting flags
 -----------------
 

Re: [LTP] cpusets: document adding/removing cpus to cpuset elaborately

[Subrata Modak]

[-- Attachment #1.1: Type: text/plain, Size: 1868 bytes --]

On Tue, Jun 16, 2009 at 4:46 PM, Nikanth Karthikesan <knikanth@suse.de>wrote:

> Writing a pid to the file, tasks adds that task to that cgroup/cpuset. But
> to
> add a cpu/mem to a cpuset, the new list of cpus should be written to the
> cpuset.mems file which would replace the old list of cpus. Make this
> clearer
> in the documentation.
>
> Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>


Hey,

Great to see that you are working on the documentation part. Have you given
a try to test the CPUSET features in the kernel with the recently added
tests from LTP(
http://ltp.cvs.sourceforge.net/viewvc/ltp/ltp/testcases/kernel/controllers/cpuset/)
? It would be great if you help us in improving them further.

Regards--
Subrata


>
> ---
>
> diff --git a/Documentation/cgroups/cpusets.txt
> b/Documentation/cgroups/cpusets.txt
> index f9ca389..1d7e978 100644
> --- a/Documentation/cgroups/cpusets.txt
> +++ b/Documentation/cgroups/cpusets.txt
> @@ -777,6 +777,18 @@ in cpuset directories:
>  # /bin/echo 1-4 > cpus         -> set cpus list to cpus 1,2,3,4
>  # /bin/echo 1,2,3,4 > cpus     -> set cpus list to cpus 1,2,3,4
>
> +To add a CPU to a cpuset, write the new list of CPUs including the
> +CPU to be added. To add 6 to the above cpuset:
> +
> +# /bin/echo 1-4,6 > cpus       -> set cpus list to cpus 1,2,3,4,6
> +
> +Similarly to remove a CPU from a cpuset, write the new list of CPUs
> +without the CPU to be removed.
> +
> +To remove all the CPUs:
> +
> +# /bin/echo "" > cpus          -> clear cpus list
> +
>  2.3 Setting flags
>  -----------------
>
>
>
>
> --
> 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/
>



-- 
Regards & Thanks--
Subrata

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Re: [LTP] cpusets: document adding/removing cpus to cpuset elaborately

[Subrata Modak]

Hi Nikanth,

On Tue, 2009-06-16 at 16:53 +0530, Subrata Modak wrote: 
> On Tue, Jun 16, 2009 at 4:46 PM, Nikanth Karthikesan
> <knikanth@suse.de> wrote:
>         Writing a pid to the file, tasks adds that task to that
>         cgroup/cpuset. But to
>         add a cpu/mem to a cpuset, the new list of cpus should be
>         written to the
>         cpuset.mems file which would replace the old list of cpus.
>         Make this clearer
>         in the documentation.
>         
>         Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> 
> 
> Hey,
> 
> Great to see that you are working on the documentation part. Have you
> given a try to test the CPUSET features in the kernel with the
> recently added tests from
> LTP(http://ltp.cvs.sourceforge.net/viewvc/ltp/ltp/testcases/kernel/controllers/cpuset/) ? It would be great if you help us in improving them further.
> 

Would you like to share something with us ?

Regards--
Subrata

> Regards--
> Subrata
> 
> 
>         
>         
>         ---
>         
>         diff --git a/Documentation/cgroups/cpusets.txt
>         b/Documentation/cgroups/cpusets.txt
>         index f9ca389..1d7e978 100644
>         --- a/Documentation/cgroups/cpusets.txt
>         +++ b/Documentation/cgroups/cpusets.txt
>         @@ -777,6 +777,18 @@ in cpuset directories:
>          # /bin/echo 1-4 > cpus         -> set cpus list to cpus
>         1,2,3,4
>          # /bin/echo 1,2,3,4 > cpus     -> set cpus list to cpus
>         1,2,3,4
>         
>         +To add a CPU to a cpuset, write the new list of CPUs
>         including the
>         +CPU to be added. To add 6 to the above cpuset:
>         +
>         +# /bin/echo 1-4,6 > cpus       -> set cpus list to cpus
>         1,2,3,4,6
>         +
>         +Similarly to remove a CPU from a cpuset, write the new list
>         of CPUs
>         +without the CPU to be removed.
>         +
>         +To remove all the CPUs:
>         +
>         +# /bin/echo "" > cpus          -> clear cpus list
>         +
>          2.3 Setting flags
>          -----------------
>         
>         
>         
>         
>         --
>         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/ 
> 
> 
> 
> -- 
> Regards & Thanks--
> Subrata 
> ------------------------------------------------------------------------------
> Crystal Reports - New Free Runtime and 30 Day Trial
> Check out the new simplified licensing option that enables unlimited
> royalty-free distribution of the report engine for externally facing 
> server and web deployment.
> http://p.sf.net/sfu/businessobjects
> _______________________________________________ Ltp-list mailing list Ltp-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ltp-list


------------------------------------------------------------------------------
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Check out the new simplified licensing option that enables unlimited
royalty-free distribution of the report engine for externally facing 
server and web deployment.
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Re: [LTP] cpusets: document adding/removing cpus to cpusetelaborately

[Nikanth Karthikesan]

>>> On 6/18/2009 at 11:01 PM, Subrata Modak <subrata@linux.vnet.ibm.com> wrote: 
> Hi Nikanth, 
>  
> On Tue, 2009-06-16 at 16:53 +0530, Subrata Modak wrote:  
> > On Tue, Jun 16, 2009 at 4:46 PM, Nikanth Karthikesan 
> > <knikanth@suse.de> wrote: 
> >         Writing a pid to the file, tasks adds that task to that 
> >         cgroup/cpuset. But to 
> >         add a cpu/mem to a cpuset, the new list of cpus should be 
> >         written to the 
> >         cpuset.mems file which would replace the old list of cpus. 
> >         Make this clearer 
> >         in the documentation. 
> >          
> >         Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>  
> >  
> > Hey, 
> >  
> > Great to see that you are working on the documentation part. Have you 
> > given a try to test the CPUSET features in the kernel with the 
> > recently added tests from 
> >  
> LTP(http://ltp.cvs.sourceforge.net/viewvc/ltp/ltp/testcases/kernel/controller 
> s/cpuset/) ? It would be great if you help us in improving them further. 
> >  
>  
> Would you like to share something with us ? 
>  

Hey Subrata

Great to hear from you. I was working  on a patch that touches cpuset, and
mis-understood the doc, hence the patch. But I haven't worked on it after that,
as I was occupied with something else.

Thanks a lot for pointing me to the LTP test cases. It should help me. Surely,
would use it when I get back to it, after I am back from vacation and and report
my experience. :)

Thanks
Nikanth

> >  
> >  
> >          
> >          
> >         --- 
> >          
> >         diff --git a/Documentation/cgroups/cpusets.txt 
> >         b/Documentation/cgroups/cpusets.txt 
> >         index f9ca389..1d7e978 100644 
> >         --- a/Documentation/cgroups/cpusets.txt 
> >         +++ b/Documentation/cgroups/cpusets.txt 
> >         @@ -777,6 +777,18 @@ in cpuset directories: 
> >          # /bin/echo 1-4 > cpus         -> set cpus list to cpus 
> >         1,2,3,4 
> >          # /bin/echo 1,2,3,4 > cpus     -> set cpus list to cpus 
> >         1,2,3,4 
> >          
> >         +To add a CPU to a cpuset, write the new list of CPUs 
> >         including the 
> >         +CPU to be added. To add 6 to the above cpuset: 
> >         + 
> >         +# /bin/echo 1-4,6 > cpus       -> set cpus list to cpus 
> >         1,2,3,4,6 
> >         + 
> >         +Similarly to remove a CPU from a cpuset, write the new list 
> >         of CPUs 
> >         +without the CPU to be removed. 
> >         + 
> >         +To remove all the CPUs: 
> >         + 
> >         +# /bin/echo "" > cpus          -> clear cpus list 
> >         + 
> >          2.3 Setting flags 
> >          ----------------- 
> >          
> >          
> >          
> >          
> >         -- 
> >         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/  
> >  
> >  
> >  
> > --  
> > Regards & Thanks-- 
> > Subrata  
> > ------------------------------------------------------------------------------ 
> > Crystal Reports - New Free Runtime and 30 Day Trial 
> > Check out the new simplified licensing option that enables unlimited 
> > royalty-free distribution of the report engine for externally facing  
> > server and web deployment. 
> > http://p.sf.net/sfu/businessobjects 
> > _______________________________________________ Ltp-list mailing list  
> Ltp-list@lists.sourceforge.net  
> https://lists.sourceforge.net/lists/listinfo/ltp-list 
>  
>  


------------------------------------------------------------------------------
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server and web deployment.
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Re: cpusets: document adding/removing cpus to cpuset elaborately

[Li Zefan]

Nikanth Karthikesan wrote:
> Writing a pid to the file, tasks adds that task to that cgroup/cpuset. But to
> add a cpu/mem to a cpuset, the new list of cpus should be written to the
> cpuset.mems file which would replace the old list of cpus. Make this clearer
> in the documentation.
> 

Though I think '>' already means overwrite so removing/adding cpus should
always writing the full list of CPUs to 'cpus', more documentation to make
cpuset usage clearer is not bad.

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

> Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
> 
> ---
> 
> diff --git a/Documentation/cgroups/cpusets.txt b/Documentation/cgroups/cpusets.txt
> index f9ca389..1d7e978 100644
> --- a/Documentation/cgroups/cpusets.txt
> +++ b/Documentation/cgroups/cpusets.txt
> @@ -777,6 +777,18 @@ in cpuset directories:
>  # /bin/echo 1-4 > cpus		-> set cpus list to cpus 1,2,3,4
>  # /bin/echo 1,2,3,4 > cpus	-> set cpus list to cpus 1,2,3,4
>  
> +To add a CPU to a cpuset, write the new list of CPUs including the
> +CPU to be added. To add 6 to the above cpuset:
> +
> +# /bin/echo 1-4,6 > cpus	-> set cpus list to cpus 1,2,3,4,6
> +
> +Similarly to remove a CPU from a cpuset, write the new list of CPUs
> +without the CPU to be removed.
> +
> +To remove all the CPUs:
> +
> +# /bin/echo "" > cpus		-> clear cpus list
> +
>  2.3 Setting flags
>  -----------------
>  

Re: cpusets: document adding/removing cpus to cpuset elaborately

[Paul Menage]

On Tue, Jun 16, 2009 at 5:45 PM, Li Zefan<lizf@cn.fujitsu.com> wrote:
> Nikanth Karthikesan wrote:
>> Writing a pid to the file, tasks adds that task to that cgroup/cpuset. But to
>> add a cpu/mem to a cpuset, the new list of cpus should be written to the
>> cpuset.mems file which would replace the old list of cpus. Make this clearer
>> in the documentation.
>>
>
> Though I think '>' already means overwrite so removing/adding cpus should
> always writing the full list of CPUs to 'cpus'

But in the context of cgroups/cpusets that's not always the case -
think of the "tasks" file.

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

Acked-by: Paul Menage <menage@google.com>

Paul