+ huge_memory-convert-do_huge_pmd_wp_page-to-use-a-folio.patch added to mm-unstable branch

+ huge_memory-convert-do_huge_pmd_wp_page-to-use-a-folio.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: huge_memory: convert do_huge_pmd_wp_page() to use a folio
has been added to the -mm mm-unstable branch.  Its filename is
     huge_memory-convert-do_huge_pmd_wp_page-to-use-a-folio.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/huge_memory-convert-do_huge_pmd_wp_page-to-use-a-folio.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: huge_memory: convert do_huge_pmd_wp_page() to use a folio
Date: Fri, 2 Sep 2022 20:46:38 +0100

Removes many calls to compound_head().  Does not remove the assumption
that a folio may not be larger than a PMD.

Link: https://lkml.kernel.org/r/20220902194653.1739778-43-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/huge_memory.c |   35 +++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)

--- a/mm/huge_memory.c~huge_memory-convert-do_huge_pmd_wp_page-to-use-a-folio
+++ a/mm/huge_memory.c
@@ -1305,6 +1305,7 @@ vm_fault_t do_huge_pmd_wp_page(struct vm
 {
 	const bool unshare = vmf->flags & FAULT_FLAG_UNSHARE;
 	struct vm_area_struct *vma = vmf->vma;
+	struct folio *folio;
 	struct page *page;
 	unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
 	pmd_t orig_pmd = vmf->orig_pmd;
@@ -1326,46 +1327,48 @@ vm_fault_t do_huge_pmd_wp_page(struct vm
 	}
 
 	page = pmd_page(orig_pmd);
+	folio = page_folio(page);
 	VM_BUG_ON_PAGE(!PageHead(page), page);
 
 	/* Early check when only holding the PT lock. */
 	if (PageAnonExclusive(page))
 		goto reuse;
 
-	if (!trylock_page(page)) {
-		get_page(page);
+	if (!folio_trylock(folio)) {
+		folio_get(folio);
 		spin_unlock(vmf->ptl);
-		lock_page(page);
+		folio_lock(folio);
 		spin_lock(vmf->ptl);
 		if (unlikely(!pmd_same(*vmf->pmd, orig_pmd))) {
 			spin_unlock(vmf->ptl);
-			unlock_page(page);
-			put_page(page);
+			folio_unlock(folio);
+			folio_put(folio);
 			return 0;
 		}
-		put_page(page);
+		folio_put(folio);
 	}
 
 	/* Recheck after temporarily dropping the PT lock. */
 	if (PageAnonExclusive(page)) {
-		unlock_page(page);
+		folio_unlock(folio);
 		goto reuse;
 	}
 
 	/*
-	 * See do_wp_page(): we can only reuse the page exclusively if there are
-	 * no additional references. Note that we always drain the LRU
-	 * pagevecs immediately after adding a THP.
+	 * See do_wp_page(): we can only reuse the folio exclusively if
+	 * there are no additional references. Note that we always drain
+	 * the LRU pagevecs immediately after adding a THP.
 	 */
-	if (page_count(page) > 1 + PageSwapCache(page) * thp_nr_pages(page))
+	if (folio_ref_count(folio) >
+			1 + folio_test_swapcache(folio) * folio_nr_pages(folio))
 		goto unlock_fallback;
-	if (PageSwapCache(page))
-		try_to_free_swap(page);
-	if (page_count(page) == 1) {
+	if (folio_test_swapcache(folio))
+		folio_free_swap(folio);
+	if (folio_ref_count(folio) == 1) {
 		pmd_t entry;
 
 		page_move_anon_rmap(page, vma);
-		unlock_page(page);
+		folio_unlock(folio);
 reuse:
 		if (unlikely(unshare)) {
 			spin_unlock(vmf->ptl);
@@ -1380,7 +1383,7 @@ reuse:
 	}
 
 unlock_fallback:
-	unlock_page(page);
+	folio_unlock(folio);
 	spin_unlock(vmf->ptl);
 fallback:
 	__split_huge_pmd(vma, vmf->pmd, vmf->address, false, NULL);
_

Patches currently in -mm which might be from willy@infradead.org are

tools-fix-compilation-after-gfp_typesh-split.patch
mm-fix-vm_bug_on-in-__delete_from_swap_cache.patch
vmscan-check-folio_test_private-not-folio_get_private.patch
support-highmem-pages-in-vmap_pages_range_noflush.patch
mm-add-vma-iterator.patch
mmap-use-the-vma-iterator-in-count_vma_pages_range.patch
proc-remove-vma-rbtree-use-from-nommu.patch
arm64-remove-mmap-linked-list-from-vdso.patch
parisc-remove-mmap-linked-list-from-cache-handling.patch
powerpc-remove-mmap-linked-list-walks.patch
s390-remove-vma-linked-list-walks.patch
x86-remove-vma-linked-list-walks.patch
xtensa-remove-vma-linked-list-walks.patch
cxl-remove-vma-linked-list-walk.patch
optee-remove-vma-linked-list-walk.patch
um-remove-vma-linked-list-walk.patch
coredump-remove-vma-linked-list-walk.patch
exec-use-vma-iterator-instead-of-linked-list.patch
fs-proc-task_mmu-stop-using-linked-list-and-highest_vm_end.patch
acct-use-vma-iterator-instead-of-linked-list.patch
perf-use-vma-iterator.patch
sched-use-maple-tree-iterator-to-walk-vmas.patch
fork-use-vma-iterator.patch
mm-khugepaged-stop-using-vma-linked-list.patch
mm-ksm-use-vma-iterators-instead-of-vma-linked-list.patch
mm-mlock-use-vma-iterator-and-maple-state-instead-of-vma-linked-list.patch
mm-pagewalk-use-vma_find-instead-of-vma-linked-list.patch
i915-use-the-vma-iterator.patch
nommu-remove-uses-of-vma-linked-list.patch
mm-vmscan-fix-a-lot-of-comments.patch
mm-add-the-first-tail-page-to-struct-folio.patch
mm-reimplement-folio_order-and-folio_nr_pages.patch
mm-add-split_folio.patch
mm-add-folio_add_lru_vma.patch
shmem-convert-shmem_writepage-to-use-a-folio-throughout.patch
shmem-convert-shmem_delete_from_page_cache-to-take-a-folio.patch
shmem-convert-shmem_replace_page-to-use-folios-throughout.patch
mm-swapfile-remove-page_swapcount.patch
mm-swapfile-convert-try_to_free_swap-to-folio_free_swap.patch
mm-swap-convert-__read_swap_cache_async-to-use-a-folio.patch
mm-swap-convert-add_to_swap_cache-to-take-a-folio.patch
mm-swap-convert-put_swap_page-to-put_swap_folio.patch
mm-convert-do_swap_page-to-use-a-folio.patch
mm-convert-do_swap_pages-swapcache-variable-to-a-folio.patch
memcg-convert-mem_cgroup_swapin_charge_page-to-mem_cgroup_swapin_charge_folio.patch
shmem-convert-shmem_mfill_atomic_pte-to-use-a-folio.patch
shmem-convert-shmem_replace_page-to-shmem_replace_folio.patch
swap-add-swap_cache_get_folio.patch
shmem-eliminate-struct-page-from-shmem_swapin_folio.patch
shmem-convert-shmem_getpage_gfp-to-shmem_get_folio_gfp.patch
shmem-convert-shmem_fault-to-use-shmem_get_folio_gfp.patch
shmem-convert-shmem_read_mapping_page_gfp-to-use-shmem_get_folio_gfp.patch
shmem-add-shmem_get_folio.patch
shmem-convert-shmem_get_partial_folio-to-use-shmem_get_folio.patch
shmem-convert-shmem_write_begin-to-use-shmem_get_folio.patch
shmem-convert-shmem_file_read_iter-to-use-shmem_get_folio.patch
shmem-convert-shmem_fallocate-to-use-a-folio.patch
shmem-convert-shmem_symlink-to-use-a-folio.patch
shmem-convert-shmem_get_link-to-use-a-folio.patch
khugepaged-call-shmem_get_folio.patch
userfaultfd-convert-mcontinue_atomic_pte-to-use-a-folio.patch
shmem-remove-shmem_getpage.patch
swapfile-convert-try_to_unuse-to-use-a-folio.patch
swapfile-convert-__try_to_reclaim_swap-to-use-a-folio.patch
swapfile-convert-unuse_pte_range-to-use-a-folio.patch
mm-convert-do_swap_page-to-use-swap_cache_get_folio.patch
mm-remove-lookup_swap_cache.patch
swap_state-convert-free_swap_cache-to-use-a-folio.patch
swap-convert-swap_writepage-to-use-a-folio.patch
mm-convert-do_wp_page-to-use-a-folio.patch
huge_memory-convert-do_huge_pmd_wp_page-to-use-a-folio.patch
madvise-convert-madvise_free_pte_range-to-use-a-folio.patch
uprobes-use-folios-more-widely-in-__replace_page.patch
ksm-use-a-folio-in-replace_page.patch
mm-convert-do_swap_page-to-use-folio_free_swap.patch
memcg-convert-mem_cgroup_swap_full-to-take-a-folio.patch
mm-remove-try_to_free_swap.patch
rmap-convert-page_move_anon_rmap-to-use-a-folio.patch
migrate-convert-__unmap_and_move-to-use-folios.patch
migrate-convert-unmap_and_move_huge_page-to-use-folios.patch
huge_memory-convert-split_huge_page_to_list-to-use-a-folio.patch
huge_memory-convert-unmap_page-to-unmap_folio.patch
mm-convert-page_get_anon_vma-to-folio_get_anon_vma.patch
rmap-remove-page_unlock_anon_vma_read.patch
uprobes-use-new_folio-in-__replace_page.patch
mm-convert-lock_page_or_retry-to-folio_lock_or_retry.patch