On Mon, 29 Mar 2010 12:03:21 +0900
Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx> wrote:
> This patch adds support for moving charge of file cache. It's enabled by setting
> bit 1 of <target cgroup>/memory.move_charge_at_immigrate.
>
> Signed-off-by: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
> ---
> Documentation/cgroups/memory.txt | 6 ++++--
> mm/memcontrol.c | 14 +++++++++++---
> 2 files changed, 15 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
> index 1b5bd04..f53d220 100644
> --- a/Documentation/cgroups/memory.txt
> +++ b/Documentation/cgroups/memory.txt
> @@ -461,10 +461,12 @@ charges should be moved.
> 0 | A charge of an anonymous page(or swap of it) used by the target task.
> | Those pages and swaps must be used only by the target task. You must
> | enable Swap Extension(see 2.4) to enable move of swap charges.
> + -----+------------------------------------------------------------------------
> + 1 | A charge of file cache mmap'ed by the target task. Those pages must be
> + | mmap'ed only by the target task.
Hmm..my English is not good but..
==
A charge of a page cache mapped by the target task. Pages mapped by multiple processes
will not be moved. This "page cache" doesn't include tmpfs.
==
Hmm, "a page mapped only by target task but belongs to other cgroup" will be moved ?
The answer is "NO.".
The code itself seems to work well. So, could you update Documentation ?
Thanks,
-Kame
>
> Note: Those pages and swaps must be charged to the old cgroup.
> -Note: More type of pages(e.g. file cache, shmem,) will be supported by other
> - bits in future.
> +Note: More type of pages(e.g. shmem) will be supported by other bits in future.
>
> 8.3 TODO
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index f6c9d42..66d2704 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -250,6 +250,7 @@ struct mem_cgroup {
> */
> enum move_type {
> MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */
> + MOVE_CHARGE_TYPE_FILE, /* private file caches */
> NR_MOVE_TYPE,
> };
>
> @@ -4192,6 +4193,8 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma,
> int usage_count = 0;
> bool move_anon = test_bit(MOVE_CHARGE_TYPE_ANON,
> &mc.to->move_charge_at_immigrate);
> + bool move_file = test_bit(MOVE_CHARGE_TYPE_FILE,
> + &mc.to->move_charge_at_immigrate);
>
> if (!pte_present(ptent)) {
> /* TODO: handle swap of shmes/tmpfs */
> @@ -4208,10 +4211,15 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma,
> if (!page || !page_mapped(page))
> return 0;
> /*
> - * TODO: We don't move charges of file(including shmem/tmpfs)
> - * pages for now.
> + * TODO: We don't move charges of shmem/tmpfs pages for now.
> */
> - if (!move_anon || !PageAnon(page))
> + if (PageAnon(page)) {
> + if (!move_anon)
> + return 0;
> + } else if (page_is_file_cache(page)) {
> + if (!move_file)
> + return 0;
> + } else
> return 0;
> if (!get_page_unless_zero(page))
> return 0;
> --
> 1.6.4
>
>
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