Re: [-mm] Add an owner to the mm_struct (v2)

Jiri Slaby
2008-03-28T10:46:43Z

On 03/28/2008 09:23 AM, Balbir Singh wrote:
> This patch removes the mem_cgroup member from mm_struct and instead adds
> an owner. This approach was suggested by Paul Menage. The advantage of
> this approach is that, once the mm->owner is known, using the subsystem
> id, the cgroup can be determined. It also allows several control groups
> that are virtually grouped by mm_struct, to exist independent of the memory
> controller i.e., without adding mem_cgroup's for each controller,
> to mm_struct.
>
> The code initially assigns mm->owner to the task and then after the
> thread group leader is identified. The mm->owner is changed to the thread
> group leader of the task later at the end of copy_process.
>
> A new config option CONFIG_MM_OWNER is added and the memory resource
> controller now depends on this config option.
>
> NOTE: This patch was developed on top of 2.6.25-rc5-mm1 and is applied on top
> of the memory-controller-move-to-own-slab patch (which is already present
> in the Andrew's patchset).
>
> These patches have been tested on a powerpc 64 bit box and on x86_64 box with
> several microbenchmarks and some simple memory controller testing.
>
> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
> ---
>
> include/linux/memcontrol.h | 14 ++++++++-
> include/linux/mm_types.h | 6 ++--
> include/linux/sched.h | 19 ++++++++++++
> init/Kconfig | 13 ++++++++
> kernel/exit.c | 66 +++++++++++++++++++++++++++++++++++++++++++++
> kernel/fork.c | 26 +++++++++++++++++
> mm/memcontrol.c | 19 +++++++-----
> 7 files changed, 151 insertions(+), 12 deletions(-)
>
> diff -puN include/linux/mm_types.h~memory-controller-add-mm-owner include/linux/mm_types.h
> --- linux-2.6.25-rc5/include/linux/mm_types.h~memory-controller-add-mm-owner 2008-03-28 09:30:47.000000000 +0530
> +++ linux-2.6.25-rc5-balbir/include/linux/mm_types.h 2008-03-28 12:26:59.000000000 +0530
> @@ -227,8 +227,10 @@ struct mm_struct {
> /* aio bits */
> rwlock_t ioctx_list_lock;
> struct kioctx *ioctx_list;
> -#ifdef CONFIG_CGROUP_MEM_RES_CTLR
> - struct mem_cgroup *mem_cgroup;
> +#ifdef CONFIG_MM_OWNER
> + spinlock_t owner_lock;
> + struct task_struct *owner; /* The thread group leader that */

Doesn't make sense to switch them (spinlock is unsigned int on x86, what's
sizeof between and after?)?