Re: [PATCH v4 8/8] hugetlb: add lockdep_assert_held() calls for hugetlb_lock

[Oscar Salvador]

On Mon, Apr 05, 2021 at 04:00:43PM -0700, 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 
> Acked-by: Michal Hocko 
> Reviewed-by: Miaohe Lin 
> Reviewed-by: Muchun Song 

Reviewed-by: Oscar Salvador 

-- 
Oscar Salvador
SUSE L3

[PATCH v4 8/8] hugetlb: add lockdep_assert_held() calls for hugetlb_lock

[Mike Kravetz]

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 
Acked-by: Michal Hocko 
Reviewed-by: Miaohe Lin 
Reviewed-by: Muchun Song 
---
 mm/hugetlb.c | 9 +
 1 file changed, 9 insertions(+)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 15b6e7aadb52..5d9f74e2b963 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;
@@ -1341,6 +1344,7 @@ 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;
 
@@ -1696,6 +1700,7 @@ 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
@@ -1945,6 +1950,7 @@ 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;
@@ -2038,6 +2044,7 @@ static void return_unused_surplus_pages(struct hstate *h,
struct page *page;
LIST_HEAD(page_list);
 
+   lockdep_assert_held(&hugetlb_lock);
/* Uncommit the reservation */
h->resv_huge_pages -= unused_resv_pages;
 
@@ -2640,6 +2647,7 @@ static void try_to_free_low(struct hstate *h, unsigned 
long count,
int i;
LIST_HEAD(page_list);
 
+   lockdep_assert_held(&hugetlb_lock);
if (hstate_is_gigantic(h))
return;
 
@@ -2681,6 +2689,7 @@ 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