mm/hugetlb-cgroup: convert hugetlb_cgroup_css_offline() to work on folios

Let's convert hugetlb_cgroup_css_offline() and
hugetlb_cgroup_move_parent() to work on folios.  hugepage_activelist
contains folios, not pages.

While at it, rename page_hcg simply to hcg, removing most of the "page"
terminology.

This removes an unnecessary call to compound_head().

Link: https://lkml.kernel.org/r/20250113131611.2554758-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index 89a8ad45a533dd5c54d053cf209a8e092fba5502..bb9578bd99f98e94746f022bd42f38969ec73cbe 100644 (file)
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -195,24 +195,23 @@ static void hugetlb_cgroup_css_free(struct cgroup_subsys_state *css)
  * cannot fail.
  */
 static void hugetlb_cgroup_move_parent(int idx, struct hugetlb_cgroup *h_cg,
-                                      struct page *page)
+                                      struct folio *folio)
 {
        unsigned int nr_pages;
        struct page_counter *counter;
-       struct hugetlb_cgroup *page_hcg;
+       struct hugetlb_cgroup *hcg;
        struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(h_cg);
-       struct folio *folio = page_folio(page);
 
-       page_hcg = hugetlb_cgroup_from_folio(folio);
+       hcg = hugetlb_cgroup_from_folio(folio);
        /*
         * 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)
+       if (!hcg || hcg != h_cg)
                goto out;
 
-       nr_pages = compound_nr(page);
+       nr_pages = folio_nr_pages(folio);
        if (!parent) {
                parent = root_h_cgroup;
                /* root has no limit */
@@ -235,13 +234,13 @@ static void hugetlb_cgroup_css_offline(struct cgroup_subsys_state *css)
 {
        struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css);
        struct hstate *h;
-       struct page *page;
+       struct folio *folio;
 
        do {
                for_each_hstate(h) {
                        spin_lock_irq(&hugetlb_lock);
-                       list_for_each_entry(page, &h->hugepage_activelist, lru)
-                               hugetlb_cgroup_move_parent(hstate_index(h), h_cg, page);
+                       list_for_each_entry(folio, &h->hugepage_activelist, lru)
+                               hugetlb_cgroup_move_parent(hstate_index(h), h_cg, folio);
 
                        spin_unlock_irq(&hugetlb_lock);
                }