The patch titled
Subject: shmem: convert shmem_write_end() to use a folio
has been added to the -mm mm-unstable branch. Its filename is
shmem-convert-shmem_write_end-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/shmem-convert-shmem_write_end-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@xxxxxxxxxxxxx>
Subject: shmem: convert shmem_write_end() to use a folio
Date: Thu, 12 Jan 2023 13:10:31 +0000
Use a folio internally to shmem_write_end() which saves a number of calls
to compound_head() and lets us get rid of the custom code to zero out the
rest of a THP and supports folios of arbitrary size.
Link: https://lkml.kernel.org/r/20230112131031.1209553-1-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 30 ++++++++++--------------------
1 file changed, 10 insertions(+), 20 deletions(-)
--- a/mm/shmem.c~shmem-convert-shmem_write_end-to-use-a-folio
+++ a/mm/shmem.c
@@ -2578,33 +2578,23 @@ shmem_write_end(struct file *file, struc
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
+ struct folio *folio = page_folio(page);
struct inode *inode = mapping->host;
if (pos + copied > inode->i_size)
i_size_write(inode, pos + copied);
- if (!PageUptodate(page)) {
- struct page *head = compound_head(page);
- if (PageTransCompound(page)) {
- int i;
-
- for (i = 0; i < HPAGE_PMD_NR; i++) {
- if (head + i == page)
- continue;
- clear_highpage(head + i);
- flush_dcache_page(head + i);
- }
- }
- if (copied < PAGE_SIZE) {
- unsigned from = pos & (PAGE_SIZE - 1);
- zero_user_segments(page, 0, from,
- from + copied, PAGE_SIZE);
+ if (!folio_test_uptodate(folio)) {
+ if (copied < folio_size(folio)) {
+ size_t from = offset_in_folio(folio, pos);
+ folio_zero_segments(folio, 0, from,
+ from + copied, folio_size(folio));
}
- SetPageUptodate(head);
+ folio_mark_uptodate(folio);
}
- set_page_dirty(page);
- unlock_page(page);
- put_page(page);
+ folio_mark_dirty(folio);
+ folio_unlock(folio);
+ folio_put(folio);
return copied;
}
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
buffer-add-b_folio-as-an-alias-of-b_page.patch
buffer-replace-obvious-uses-of-b_page-with-b_folio.patch
buffer-use-b_folio-in-touch_buffer.patch
buffer-use-b_folio-in-end_buffer_async_read.patch
buffer-use-b_folio-in-end_buffer_async_write.patch
page_io-remove-buffer_head-include.patch
buffer-use-b_folio-in-mark_buffer_dirty.patch
gfs2-replace-obvious-uses-of-b_page-with-b_folio.patch
jbd2-replace-obvious-uses-of-b_page-with-b_folio.patch
nilfs2-replace-obvious-uses-of-b_page-with-b_folio.patch
reiserfs-replace-obvious-uses-of-b_page-with-b_folio.patch
mpage-use-b_folio-in-do_mpage_readpage.patch
mm-memcg-add-folio_memcg_check.patch
mm-remove-folio_pincount_ptr-and-head_compound_pincount.patch
mm-convert-head_subpages_mapcount-into-folio_nr_pages_mapped.patch
doc-clarify-refcount-section-by-referring-to-folios-pages.patch
mm-convert-total_compound_mapcount-to-folio_total_mapcount.patch
mm-convert-page_remove_rmap-to-use-a-folio-internally.patch
mm-convert-page_add_anon_rmap-to-use-a-folio-internally.patch
mm-convert-page_add_file_rmap-to-use-a-folio-internally.patch
mm-add-folio_add_new_anon_rmap.patch
mm-add-folio_add_new_anon_rmap-fix-2.patch
page_alloc-use-folio-fields-directly.patch
mm-use-a-folio-in-hugepage_add_anon_rmap-and-hugepage_add_new_anon_rmap.patch
mm-use-entire_mapcount-in-__page_dup_rmap.patch
mm-debug-remove-call-to-head_compound_mapcount.patch
hugetlb-remove-uses-of-folio_mapcount_ptr.patch
mm-convert-page_mapcount-to-use-folio_entire_mapcount.patch
mm-remove-head_compound_mapcount-and-_ptr-functions.patch
mm-reimplement-compound_order.patch
mm-reimplement-compound_nr.patch
mm-convert-set_compound_page_dtor-and-set_compound_order-to-folios.patch
mm-convert-is_transparent_hugepage-to-use-a-folio.patch
mm-convert-destroy_large_folio-to-use-folio_dtor.patch
hugetlb-remove-uses-of-compound_dtor-and-compound_nr.patch
mm-remove-first-tail-page-members-from-struct-page.patch
doc-correct-struct-folio-kernel-doc.patch
mm-move-page-deferred_list-to-folio-_deferred_list.patch
mm-huge_memory-remove-page_deferred_list.patch
mm-huge_memory-convert-get_deferred_split_queue-to-take-a-folio.patch
mm-convert-deferred_split_huge_page-to-deferred_split_folio.patch
shmem-convert-shmem_write_end-to-use-a-folio.patch
