The patch titled
Subject: mm/shmem: convert shmem_add_to_page_cache to take a folio
has been added to the -mm mm-unstable branch. Its filename is
mm-shmem-convert-shmem_add_to_page_cache-to-take-a-folio.patch
This patch should soon 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@xxxxxxxxxxxxx>
Subject: mm/shmem: convert shmem_add_to_page_cache to take a folio
Shrinks shmem_add_to_page_cache() by 16 bytes. All the callers grow,
but this is temporary as they will all be converted to folios soon.
Link: https://lkml.kernel.org/r/20220504182857.4013401-19-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 59 +++++++++++++++++++++++++++------------------------
1 file changed, 32 insertions(+), 27 deletions(-)
--- a/mm/shmem.c~mm-shmem-convert-shmem_add_to_page_cache-to-take-a-folio
+++ a/mm/shmem.c
@@ -696,36 +696,35 @@ static unsigned long shmem_unused_huge_s
/*
* Like add_to_page_cache_locked, but error if expected item has gone.
*/
-static int shmem_add_to_page_cache(struct page *page,
+static int shmem_add_to_page_cache(struct folio *folio,
struct address_space *mapping,
pgoff_t index, void *expected, gfp_t gfp,
struct mm_struct *charge_mm)
{
- XA_STATE_ORDER(xas, &mapping->i_pages, index, compound_order(page));
- unsigned long nr = compound_nr(page);
+ XA_STATE_ORDER(xas, &mapping->i_pages, index, folio_order(folio));
+ long nr = folio_nr_pages(folio);
int error;
- VM_BUG_ON_PAGE(PageTail(page), page);
- VM_BUG_ON_PAGE(index != round_down(index, nr), page);
- VM_BUG_ON_PAGE(!PageLocked(page), page);
- VM_BUG_ON_PAGE(!PageSwapBacked(page), page);
- VM_BUG_ON(expected && PageTransHuge(page));
-
- page_ref_add(page, nr);
- page->mapping = mapping;
- page->index = index;
+ VM_BUG_ON_FOLIO(index != round_down(index, nr), folio);
+ VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
+ VM_BUG_ON_FOLIO(!folio_test_swapbacked(folio), folio);
+ VM_BUG_ON(expected && folio_test_large(folio));
+
+ folio_ref_add(folio, nr);
+ folio->mapping = mapping;
+ folio->index = index;
- if (!PageSwapCache(page)) {
- error = mem_cgroup_charge(page_folio(page), charge_mm, gfp);
+ if (!folio_test_swapcache(folio)) {
+ error = mem_cgroup_charge(folio, charge_mm, gfp);
if (error) {
- if (PageTransHuge(page)) {
+ if (folio_test_pmd_mappable(folio)) {
count_vm_event(THP_FILE_FALLBACK);
count_vm_event(THP_FILE_FALLBACK_CHARGE);
}
goto error;
}
}
- cgroup_throttle_swaprate(page, gfp);
+ folio_throttle_swaprate(folio, gfp);
do {
xas_lock_irq(&xas);
@@ -737,16 +736,16 @@ static int shmem_add_to_page_cache(struc
xas_set_err(&xas, -EEXIST);
goto unlock;
}
- xas_store(&xas, page);
+ xas_store(&xas, folio);
if (xas_error(&xas))
goto unlock;
- if (PageTransHuge(page)) {
+ if (folio_test_pmd_mappable(folio)) {
count_vm_event(THP_FILE_ALLOC);
- __mod_lruvec_page_state(page, NR_SHMEM_THPS, nr);
+ __lruvec_stat_mod_folio(folio, NR_SHMEM_THPS, nr);
}
mapping->nrpages += nr;
- __mod_lruvec_page_state(page, NR_FILE_PAGES, nr);
- __mod_lruvec_page_state(page, NR_SHMEM, nr);
+ __lruvec_stat_mod_folio(folio, NR_FILE_PAGES, nr);
+ __lruvec_stat_mod_folio(folio, NR_SHMEM, nr);
unlock:
xas_unlock_irq(&xas);
} while (xas_nomem(&xas, gfp));
@@ -758,8 +757,8 @@ unlock:
return 0;
error:
- page->mapping = NULL;
- page_ref_sub(page, nr);
+ folio->mapping = NULL;
+ folio_ref_sub(folio, nr);
return error;
}
@@ -1691,7 +1690,8 @@ static int shmem_swapin_page(struct inod
struct address_space *mapping = inode->i_mapping;
struct shmem_inode_info *info = SHMEM_I(inode);
struct mm_struct *charge_mm = vma ? vma->vm_mm : NULL;
- struct page *page;
+ struct page *page = NULL;
+ struct folio *folio;
swp_entry_t swap;
int error;
@@ -1741,7 +1741,8 @@ static int shmem_swapin_page(struct inod
goto failed;
}
- error = shmem_add_to_page_cache(page, mapping, index,
+ folio = page_folio(page);
+ error = shmem_add_to_page_cache(folio, mapping, index,
swp_to_radix_entry(swap), gfp,
charge_mm);
if (error)
@@ -1792,6 +1793,7 @@ static int shmem_getpage_gfp(struct inod
struct shmem_inode_info *info = SHMEM_I(inode);
struct shmem_sb_info *sbinfo;
struct mm_struct *charge_mm;
+ struct folio *folio;
struct page *page;
pgoff_t hindex = index;
gfp_t huge_gfp;
@@ -1906,7 +1908,8 @@ alloc_nohuge:
if (sgp == SGP_WRITE)
__SetPageReferenced(page);
- error = shmem_add_to_page_cache(page, mapping, hindex,
+ folio = page_folio(page);
+ error = shmem_add_to_page_cache(folio, mapping, hindex,
NULL, gfp & GFP_RECLAIM_MASK,
charge_mm);
if (error)
@@ -2328,6 +2331,7 @@ int shmem_mfill_atomic_pte(struct mm_str
gfp_t gfp = mapping_gfp_mask(mapping);
pgoff_t pgoff = linear_page_index(dst_vma, dst_addr);
void *page_kaddr;
+ struct folio *folio;
struct page *page;
int ret;
pgoff_t max_off;
@@ -2386,7 +2390,8 @@ int shmem_mfill_atomic_pte(struct mm_str
if (unlikely(pgoff >= max_off))
goto out_release;
- ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL,
+ folio = page_folio(page);
+ ret = shmem_add_to_page_cache(folio, mapping, pgoff, NULL,
gfp & GFP_RECLAIM_MASK, dst_mm);
if (ret)
goto out_release;
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
shmem-convert-shmem_alloc_hugepage-to-use-vma_alloc_folio.patch
mm-huge_memory-convert-do_huge_pmd_anonymous_page-to-use-vma_alloc_folio.patch
alpha-fix-alloc_zeroed_user_highpage_movable.patch
mm-remove-alloc_pages_vma.patch
vmscan-use-folio_mapped-in-shrink_page_list.patch
vmscan-convert-the-writeback-handling-in-shrink_page_list-to-folios.patch
swap-turn-get_swap_page-into-folio_alloc_swap.patch
swap-convert-add_to_swap-to-take-a-folio.patch
vmscan-convert-dirty-page-handling-to-folios.patch
vmscan-convert-page-buffer-handling-to-use-folios.patch
vmscan-convert-lazy-freeing-to-folios.patch
vmscan-move-initialisation-of-mapping-down.patch
vmscan-convert-the-activate_locked-portion-of-shrink_page_list-to-folios.patch
mm-allow-can_split_folio-to-be-called-when-thp-are-disabled.patch
vmscan-remove-remaining-uses-of-page-in-shrink_page_list.patch
mm-shmem-use-a-folio-in-shmem_unused_huge_shrink.patch
mm-swap-add-folio_throttle_swaprate.patch
mm-shmem-convert-shmem_add_to_page_cache-to-take-a-folio.patch
mm-shmem-turn-shmem_should_replace_page-into-shmem_should_replace_folio.patch
mm-shmem-add-shmem_alloc_folio.patch
mm-shmem-convert-shmem_alloc_and_acct_page-to-use-a-folio.patch
mm-shmem-convert-shmem_getpage_gfp-to-use-a-folio.patch
mm-shmem-convert-shmem_swapin_page-to-shmem_swapin_folio.patch
mm-add-folio_mapping_flags.patch
mm-add-folio_test_movable.patch
mm-migrate-convert-move_to_new_page-into-move_to_new_folio.patch
