On Fri 15-06-12 16:01:03, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
>
> page's hugetlb cgroup assign and moving to active list should happen with
> hugetlb_lock held. Otherwise when we remove the hugetlb cgroup we would
> iterate the active list and will find page with NULL hugetlb cgroup values.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Michal Hocko <mhocko@xxxxxxx>
> ---
> mm/hugetlb.c | 14 +++++++++-----
> mm/hugetlb_cgroup.c | 3 +--
> 2 files changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index ec7b86e..10160cb 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1150,9 +1150,13 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
> }
> spin_lock(&hugetlb_lock);
> page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
> - spin_unlock(&hugetlb_lock);
> -
> - if (!page) {
> + if (page) {
> + /* update page cgroup details */
> + hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h),
> + h_cg, page);
> + spin_unlock(&hugetlb_lock);
> + } else {
> + spin_unlock(&hugetlb_lock);
> page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
> if (!page) {
> hugetlb_cgroup_uncharge_cgroup(idx,
> @@ -1163,14 +1167,14 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
> }
> spin_lock(&hugetlb_lock);
> list_move(&page->lru, &h->hugepage_activelist);
> + hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h),
> + h_cg, page);
> spin_unlock(&hugetlb_lock);
> }
>
> set_page_private(page, (unsigned long)spool);
>
> vma_commit_reservation(h, vma, addr);
> - /* update page cgroup details */
> - hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page);
> return page;
> }
>
> diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
> index 8e7ca0a..d4f3f7b 100644
> --- a/mm/hugetlb_cgroup.c
> +++ b/mm/hugetlb_cgroup.c
> @@ -218,6 +218,7 @@ done:
> return ret;
> }
>
> +/* Should be called with hugetlb_lock held */
> void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
> struct hugetlb_cgroup *h_cg,
> struct page *page)
> @@ -225,9 +226,7 @@ void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
> if (hugetlb_cgroup_disabled() || !h_cg)
> return;
>
> - spin_lock(&hugetlb_lock);
> set_hugetlb_cgroup(page, h_cg);
> - spin_unlock(&hugetlb_lock);
> return;
> }
>
> --
> 1.7.10
>
--
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9
Czech Republic
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