On Wed 24-03-21 17:28:35, Mike Kravetz wrote:
> After making hugetlb lock irq safe and separating some functionality
> done under the lock, add some lockdep_assert_held to help verify
> locking.
>
> Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
> ---
> mm/hugetlb.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index e4c441b878f2..de5b3cf4a155 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1062,6 +1062,8 @@ static bool vma_has_reserves(struct vm_area_struct *vma, long chg)
> static void enqueue_huge_page(struct hstate *h, struct page *page)
> {
> int nid = page_to_nid(page);
> +
> + lockdep_assert_held(&hugetlb_lock);
> list_move(&page->lru, &h->hugepage_freelists[nid]);
> h->free_huge_pages++;
> h->free_huge_pages_node[nid]++;
> @@ -1073,6 +1075,7 @@ static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid)
> struct page *page;
> bool pin = !!(current->flags & PF_MEMALLOC_PIN);
>
> + lockdep_assert_held(&hugetlb_lock);
> list_for_each_entry(page, &h->hugepage_freelists[nid], lru) {
> if (pin && !is_pinnable_page(page))
> continue;
> @@ -1345,6 +1348,7 @@ static void remove_hugetlb_page(struct hstate *h, struct page *page,
> {
> int nid = page_to_nid(page);
>
> + lockdep_assert_held(&hugetlb_lock);
> if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
> return;
>
> @@ -1690,6 +1694,7 @@ static struct page *remove_pool_huge_page(struct hstate *h,
> int nr_nodes, node;
> struct page *page = NULL;
>
> + lockdep_assert_held(&hugetlb_lock);
> for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) {
> /*
> * If we're returning unused surplus pages, only examine
> @@ -1939,6 +1944,7 @@ static int gather_surplus_pages(struct hstate *h, long delta)
> long needed, allocated;
> bool alloc_ok = true;
>
> + lockdep_assert_held(&hugetlb_lock);
> needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
> if (needed <= 0) {
> h->resv_huge_pages += delta;
> @@ -2032,6 +2038,7 @@ static void return_unused_surplus_pages(struct hstate *h,
> struct page *page, *t_page;
> struct list_head page_list;
>
> + lockdep_assert_held(&hugetlb_lock);
> /* Uncommit the reservation */
> h->resv_huge_pages -= unused_resv_pages;
>
> @@ -2527,6 +2534,7 @@ static void try_to_free_low(struct hstate *h, unsigned long count,
> struct list_head page_list;
> struct page *page, *next;
>
> + lockdep_assert_held(&hugetlb_lock);
> if (hstate_is_gigantic(h))
> return;
>
> @@ -2573,6 +2581,7 @@ static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed,
> {
> int nr_nodes, node;
>
> + lockdep_assert_held(&hugetlb_lock);
> VM_BUG_ON(delta != -1 && delta != 1);
>
> if (delta < 0) {
> --
> 2.30.2
>
--
Michal Hocko
SUSE Labs
