| [Patch 01/05]- Containers: Documentation on using containers [message #6368] |
Fri, 15 September 2006 01:38  |
Rohit Seth
Messages: 101
Registered: August 2006
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Senior Member |
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This patch contains the Documentation for using containers.
Signed-off-by: Rohit Seth <rohitseth@google.com>
Documentation/containers.txt | 42 ++++++++++++++++++++++++++++++++++++++++++
1 files changed, 42 insertions(+)
--- linux-2.6.18-rc6-mm2.org/Documentation/containers.txt 1969-12-31 16:00:00.000000000 -0800
+++ linux-2.6.18-rc6-mm2.ctn/Documentation/containers.txt 2006-09-14 17:13:48.000000000 -0700
@@ -0,0 +1,42 @@
+This file contains information about how to use containers. Configfs support
+is needed in kernel as the container's user interface is through configfs. So
+first enable CONFIG_CONFIGFS_FS and CONFIG_CONTAINERS and recompile the kernel.
+
+1- Mount a configfs (for example):
+ mount -t configfs none /mnt/configfs
+ This will create a /mnt/configfs mount point.
+
+2- As the support of containers is built into kernel, so the mount point
+ /mnt/configfs will automatically contain a directory "containers"
+
+3- Create a container by name test_container
+ cd /mnt/configfs/containers
+ mkdir test_container
+
+All the current implemented attributes in the kernel will show up in the
+directory /configfs/containers/test_container
+
+4- Add a task to container
+ cd /mnt/configfs/cotnainers/test_container
+ echo <pid> > addtask
+
+Now the <pid> and its subsequently forked children will belong to container
+test_container.
+
+5- Remove a task from container
+ echo <pid> rmtask
+
+6- Set a page limit for the container
+ echo some_number_of_pages > page_limit
+
+7- Read the id for the container
+ cat id
+
+8- Get the statistics for this container
+ cat num* (will print active pages, anon_pages, file_pages, num_files,
+ and num_task)
+ cat *hits (will print page_limit_hits and task_limit_hits: the number
+ of times container has gone over page_limit and task_limit)
+9- Freeing a container
+ cd /mnt/configfs/containers/
+ rmdir test_container
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| Re: [Patch 01/05]- Containers: Documentation on using containers [message #6413 is a reply to message #6368] |
Fri, 15 September 2006 18:19  |
Rohit Seth
Messages: 101
Registered: August 2006
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Senior Member |
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On Fri, 2006-09-15 at 19:44 +0200, Björn Steinbrink wrote:
> On 2006.09.15 09:45:25 -0700, Rohit Seth wrote:
> > On Fri, 2006-09-15 at 08:15 +0200, Rolf Eike Beer wrote:
> > > Rohit Seth wrote:
> > > > This patch contains the Documentation for using containers.
> > >
> > > > +5- Remove a task from container
> > > > + echo <pid> rmtask
> > >
> > > echo <pid> > rmtask?
> > >
> >
> > rmtask is an attribute defined in test_container directory. So, first
> > you have to cd into container directory
> > (cd /mnt/configfs/containers/test_container and then execute this
> > command)
>
> The > is missing in the patch though, guess that's what Rolf wanted to
> point out ;)
>
Aha. Will fix it.
> >
> > > Please also give a short description what containers are for. From what I read
> > > here I can only guess it's about gettings some statistics about a group of
> > > tasks.
> >
> > Containers allow different workloads to be run on the same platform with
> > limits defined on per container basis. This basically allows a single
> > platform to be (soft) partitioned among different workloads (each of
> > which could be running many tasks). The limits could be amount of
> > memory, number of tasks among other features. These two features are
> > already implemented in the patch set that I posted. But it is possible
> > to add other controllers like CPU that allows only finite amount of time
> > to the processes belonging to a container.
> >
> > Currently this patch set is only tracking user memory (both file based
> > and anonymous). The memory handler is currently deactivating pages
> > belonging to a container that has gone over the limit. Even though this
> > allows containers to go over board their limits but 1- once they are
> > over the limit then they run in degraded manner and 2- if there is any
> > memory pressure then the (extra) pages belonging to this container are
> > the prime candidates for swapping (for example). The statistics that
> > are shown in each container directory are the current values of each
> > resource consumption.
> >
> > Please let me know if you need any more specific information about the
> > patch set.
>
> A general description for the containers needs to go into Documentation/
> along with the usage example, so that potential users know what to do
> with it. The above seems fine, just remove the "this patch" references.
>
Okay.
Thanks,
-rohit
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| Re: [Patch 01/05]- Containers: Documentation on using containers [message #6511 is a reply to message #6368] |
Tue, 19 September 2006 16:30 |
Rohit Seth
Messages: 101
Registered: August 2006
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Senior Member |
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On Tue, 2006-09-19 at 11:32 -0400, Valdis.Kletnieks@vt.edu wrote:
> On Thu, 14 Sep 2006 18:38:33 PDT, Rohit Seth said:
>
> (Sorry for the late reply...)
>
>
> > --- linux-2.6.18-rc6-mm2.org/Documentation/containers.txt 1969-12-31 16:00:00.000000000 -0800
> > +++ linux-2.6.18-rc6-mm2.ctn/Documentation/containers.txt 2006-09-14 17:13:48.000000000 -0700
>
> > +5- Remove a task from container
> > + echo <pid> rmtask
>
> echo <pid> > rmtask
>
> is what I think was intended. Also, I'm not sure <pid> is the best
> meta-syntax - anybody got a better idea?
>
Fixed that.
> > +9- Freeing a container
> > + cd /mnt/configfs/containers/
> > + rmdir test_container
>
> What happens if you try to remove a container that still has active tasks? Are
> you relying on the VFS to catch the 'non-empty directory'? (of course, 'rm -r'
> has predictable semantics here).
>
When a rmdir operation is done on a directory, then all tasks have to
move out of container (before we the rmdir operation is complete). This
removal of tasks from a container is done as part of
container_remove_tasks.
> I see support for "add a task" and "remove a task", but none for listing
> the current tasks in the container?
This is one of the TODO items that I've listed. Will be there soon.
thanks,
-rohit
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| Re: [Patch 01/05]- Containers: Documentation on using containers [message #6514 is a reply to message #6368] |
Tue, 19 September 2006 15:32 |
Valdis.Kletnieks
Messages: 5
Registered: September 2006
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Junior Member |
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On Thu, 14 Sep 2006 18:38:33 PDT, Rohit Seth said:
(Sorry for the late reply...)
> --- linux-2.6.18-rc6-mm2.org/Documentation/containers.txt 1969-12-31 16:00:00.000000000 -0800
> +++ linux-2.6.18-rc6-mm2.ctn/Documentation/containers.txt 2006-09-14 17:13:48.000000000 -0700
> +5- Remove a task from container
> + echo <pid> rmtask
echo <pid> > rmtask
is what I think was intended. Also, I'm not sure <pid> is the best
meta-syntax - anybody got a better idea?
> +9- Freeing a container
> + cd /mnt/configfs/containers/
> + rmdir test_container
What happens if you try to remove a container that still has active tasks? Are
you relying on the VFS to catch the 'non-empty directory'? (of course, 'rm -r'
has predictable semantics here).
I see support for "add a task" and "remove a task", but none for listing
the current tasks in the container?
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