Re: [PATCH] Add cgroup support for enabling controllers at boottime

From: Randy Dunlap
Date: Thu Mar 06 2008 - 14:13:57 EST


On Fri, 07 Mar 2008 00:29:52 +0530 Balbir Singh wrote:

> From: Paul Menage <menage@xxxxxxxxxx>
>
> The effects of cgroup_disable=foo are:
>
> - foo doesn't show up in /proc/cgroups
> - foo isn't auto-mounted if you mount all cgroups in a single hierarchy
> - foo isn't visible as an individually mountable subsystem
>
> As a result there will only ever be one call to foo->create(), at init
> time; all processes will stay in this group, and the group will never
> be mounted on a visible hierarchy. Any additional effects (e.g. not
> allocating metadata) are up to the foo subsystem.
>
> This doesn't handle early_init subsystems (their "disabled" bit isn't
> set be, but it could easily be extended to do so if any of the early_init
> systems wanted it - I think it would just involve some nastier parameter
> processing since it would occur before the command-line argument parser
> had been run.
>
> [Balbir added Documentation/kernel-parameters updates]
>
> Signed-off-by: Paul Menage <menage@xxxxxxxxxx>
> Signed-off-by: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
> ---
>
> Documentation/kernel-parameters.txt | 4 ++++
> include/linux/cgroup.h | 1 +
> kernel/cgroup.c | 27 +++++++++++++++++++++++++--
> 3 files changed, 30 insertions(+), 2 deletions(-)
>
> diff -puN Documentation/kernel-parameters.txt~cgroup_disable Documentation/kernel-parameters.txt
> --- linux-2.6.25-rc4/Documentation/kernel-parameters.txt~cgroup_disable 2008-03-06 17:57:32.000000000 +0530
> +++ linux-2.6.25-rc4-balbir/Documentation/kernel-parameters.txt 2008-03-06 18:00:32.000000000 +0530
> @@ -383,6 +383,10 @@ and is between 256 and 4096 characters.
> ccw_timeout_log [S390]
> See Documentation/s390/CommonIO for details.
>
> + cgroup_disable= [KNL] Enable disable a particular controller

So it can enable or disable? or the text has extra text?

> + Format: {name of the controller}
> + See /proc/cgroups for a list of compiled controllers
> +
> checkreqprot [SELINUX] Set initial checkreqprot flag value.
> Format: { "0" | "1" }
> See security/selinux/Kconfig help text.


---
~Randy
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