[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Wed, 2 Feb 2011 14:56:05 -0800
From: jacob pan <jacob.jun.pan@...ux.intel.com>
To: "Kirill A. Shutsemov" <kirill@...temov.name>
Cc: Paul Menage <menage@...gle.com>, Li Zefan <lizf@...fujitsu.com>,
containers@...ts.linux-foundation.org,
Arjan van de Ven <arjan@...ux.intel.com>,
linux-kernel@...r.kernel.org, Matt Helsley <matthltc@...ibm.com>
Subject: Re: [PATCH, v3 2/2] cgroups: introduce timer slack subsystem
On Wed, 2 Feb 2011 22:47:36 +0200
"Kirill A. Shutsemov" <kirill@...temov.name> wrote:
> From: Kirill A. Shutemov <kirill@...temov.name>
>
> Provides a way of tasks grouping by timer slack value. Introduces per
> cgroup max and min timer slack value. When a task attaches to a
> cgroup, its timer slack value adjusts (if needed) to fit min-max
> range.
>
> It also provides a way to set timer slack value for all tasks in the
> cgroup at once.
>
> This functionality is useful in mobile devices where certain
> background apps are attached to a cgroup and minimum wakeups are
> desired.
>
> Signed-off-by: Kirill A. Shutemov <kirill@...temov.name>
> Idea-by: Jacob Pan <jacob.jun.pan@...ux.intel.com>
> ---
> include/linux/cgroup_subsys.h | 6 +
> include/linux/init_task.h | 4 +-
> init/Kconfig | 10 ++
> kernel/Makefile | 1 +
> kernel/cgroup_timer_slack.c | 242
> +++++++++++++++++++++++++++++++++++++++++
> +
> +static int cgroup_timer_slack_check(struct task_struct *task,
> + unsigned long slack_ns)
> +{
> + struct cgroup_subsys_state *css;
> + struct timer_slack_cgroup *tslack_cgroup;
> +
use rcu_read_lock()/unlock?
lockdep complains unprotected rcu dereference check.
> + css = task_subsys_state(task, timer_slack_subsys.subsys_id);
> + tslack_cgroup = container_of(css, struct timer_slack_cgroup,
> css); +
> + if (slack_ns < tslack_cgroup->min_slack_ns)
> + return -EPERM;
> + if (slack_ns > tslack_cgroup->max_slack_ns)
> + return -EPERM;
> + return 0;
> +}
> +
> +
> +static struct cftype files[] = {
> + {
> + .name = "set_slack_ns",
> + .write_u64 = tslack_write_set_slack_ns,
> + },
should we also allow reading of the current slack_ns?
> + {
> + .name = "min_slack_ns",
> + .private = TIMER_SLACK_MIN,
> + .read_u64 = tslack_read_range,
> + .write_u64 = tslack_write_range,
> + },
> + {
> + .name = "max_slack_ns",
> + .private = TIMER_SLACK_MAX,
> + .read_u64 = tslack_read_range,
> + .write_u64 = tslack_write_range,
> + },
> +};
> +
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists