On Wed 13-06-12 15:57:31, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
>
> This patch add support for cgroup removal. If we don't have parent
> cgroup, the charges are moved to root cgroup.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Michal Hocko <mhocko@xxxxxxx>
> ---
> mm/hugetlb_cgroup.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 68 insertions(+), 2 deletions(-)
>
> diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
> index 0f2f6ac..a3a68a4 100644
> --- a/mm/hugetlb_cgroup.c
> +++ b/mm/hugetlb_cgroup.c
> @@ -107,10 +107,76 @@ static void hugetlb_cgroup_destroy(struct cgroup *cgroup)
> kfree(h_cgroup);
> }
>
> +
> +/*
> + * Should be called with hugetlb_lock held.
> + * Since we are holding hugetlb_lock, pages cannot get moved from
> + * active list or uncharged from the cgroup, So no need to get
> + * page reference and test for page active here. This function
> + * cannot fail.
> + */
> +static void hugetlb_cgroup_move_parent(int idx, struct cgroup *cgroup,
> + struct page *page)
> +{
> + int csize;
> + struct res_counter *counter;
> + struct res_counter *fail_res;
> + struct hugetlb_cgroup *page_hcg;
> + struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup);
> + struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(cgroup);
> +
> + page_hcg = hugetlb_cgroup_from_page(page);
> + /*
> + * We can have pages in active list without any cgroup
> + * ie, hugepage with less than 3 pages. We can safely
> + * ignore those pages.
> + */
> + if (!page_hcg || page_hcg != h_cg)
> + goto out;
> +
> + csize = PAGE_SIZE << compound_order(page);
> + if (!parent) {
> + parent = root_h_cgroup;
> + /* root has no limit */
> + res_counter_charge_nofail(&parent->hugepage[idx],
> + csize, &fail_res);
> + }
> + counter = &h_cg->hugepage[idx];
> + res_counter_uncharge_until(counter, counter->parent, csize);
> +
> + set_hugetlb_cgroup(page, parent);
> +out:
> + return;
> +}
> +
> +/*
> + * Force the hugetlb cgroup to empty the hugetlb resources by moving them to
> + * the parent cgroup.
> + */
> static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup)
> {
> - /* We will add the cgroup removal support in later patches */
> - return -EBUSY;
> + struct hstate *h;
> + struct page *page;
> + int ret = 0, idx = 0;
> +
> + do {
> + if (cgroup_task_count(cgroup) ||
> + !list_empty(&cgroup->children)) {
> + ret = -EBUSY;
> + goto out;
> + }
> + for_each_hstate(h) {
> + spin_lock(&hugetlb_lock);
> + list_for_each_entry(page, &h->hugepage_activelist, lru)
> + hugetlb_cgroup_move_parent(idx, cgroup, page);
> +
> + spin_unlock(&hugetlb_lock);
> + idx++;
> + }
> + cond_resched();
> + } while (hugetlb_cgroup_have_usage(cgroup));
> +out:
> + return ret;
> }
>
> int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
> --
> 1.7.10
>
--
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9
Czech Republic
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>