lkml.org 
[lkml]   [2008]   [Jun]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 4/6] res_counter: basic hierarchy support
On Fri, 13 Jun 2008 18:34:02 +0900 KAMEZAWA Hiroyuki wrote:

> Add a hierarhy support to res_counter. This patch itself just supports
> "No Hierarchy" hierarchy, as a default/basic hierarchy system.
>
> Changelog: v3 -> v4.
> - cut out from hardwall hierarchy patch set.
> - just support "No hierarchy" model.
>
> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> ---
> Documentation/controllers/resource_counter.txt | 27 +++++-
> include/linux/res_counter.h | 15 +++
> kernel/res_counter.c | 107 ++++++++++++++++++++-----
> mm/memcontrol.c | 1
> 4 files changed, 129 insertions(+), 21 deletions(-)
>
> Index: linux-2.6.26-rc5-mm3/kernel/res_counter.c
> ===================================================================
> --- linux-2.6.26-rc5-mm3.orig/kernel/res_counter.c
> +++ linux-2.6.26-rc5-mm3/kernel/res_counter.c
> +
>
> +/**
> + * res_counter_set_ops() -- reset res->counter.ops to be passed ops.
> + * @coutner: a counter to be set ops.

typo:
* @counter:

> + * @ops: res_counter_ops
> + *
> + * This operations is allowed only when there is no parent or parent's
> + * hierarchy_model == RES_CONT_NO_HIERARCHY. returns 0 at success.
> + */
> +
> +int res_counter_set_ops(struct res_counter *counter,
> + struct res_counter_ops *ops)
> +{
> + struct res_counter *parent;
> + /*
> + * This operation is allowed only when parents's hierarchy
> + * is NO_HIERARCHY or this is ROOT.
> + */
> + parent = counter->parent;
> + if (parent && parent->ops.hierarchy_model != RES_CONT_NO_HIERARCHY)
> + return -EINVAL;
> +
> + counter->ops = *ops;
> +
> + return 0;
> +}
> +
> +
> int res_counter_charge_locked(struct res_counter *counter, unsigned long val)
> {
> if (counter->usage + val > counter->limit) {

> Index: linux-2.6.26-rc5-mm3/Documentation/controllers/resource_counter.txt
> ===================================================================
> --- linux-2.6.26-rc5-mm3.orig/Documentation/controllers/resource_counter.txt
> +++ linux-2.6.26-rc5-mm3/Documentation/controllers/resource_counter.txt
> @@ -39,11 +39,14 @@ to work with it.
> The failcnt stands for "failures counter". This is the number of
> resource allocation attempts that failed.
>
> - e. res_counter_ops.
> + e. parent
> + parent of this res_counter under hierarchy.
> +
> + f. res_counter_ops.
> Callbacks for helping resource_counter per each subsystem.
> - shrink_usage() .... called at limit change (decrease).
>
> - f. spinlock_t lock
> + g. spinlock_t lock
>
> Protects changes of the above values.
>
> @@ -157,7 +160,25 @@ counter fields. They are recommended to
> Returns 0 at success. Any error code is acceptable but -EBUSY will be
> suitable to show "the kernel can't shrink usage."
>
> -6. Usage example
> +6. Hierarchy
> +
> + Groups of res_counter can be controlled under some tree (cgroup tree).
> + Taking the tree into account, res_counter can be under some hierarchical
> + control. THe res_counter itself supports hierarchy_model and calls

The

> + registered callbacks at suitable events.
> +
> + For keeping sanity of hierarchy, hierarchy_model of a res_counter can be
> + changed when parent's hierarchy_model is RES_CONT_NO_HIERARCHY.
> + res_counter doesn't count # of children by itself but some subysystem should
> + be aware that it has no children if necessary.
> + (don't want to fully duplicate cgroup's hierarchy. Cost of remembering parent
> + is cheap.)
> +
> + a. Independent hierarchy (RES_CONT_NO_HIERARCHY) model
> + This is no relationship between parent and children.
> +
> +
> +7. Usage example
>
> a. Declare a task group (take a look at cgroups subsystem for this) and
> fold a res_counter into it


---
~Randy
Linux Plumbers Conference, 17-19 September 2008, Portland, Oregon USA
http://linuxplumbersconf.org/

\
 
 \ /
  Last update: 2008-06-24 00:53    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site