The patch titled
Subject: mm: remove stale example from comment
has been added to the -mm mm-unstable branch. Its filename is
mm-remove-stale-example-from-comment.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-remove-stale-example-from-comment.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: mm: remove stale example from comment
Date: Mon, 11 Dec 2023 16:22:10 +0000
folio_add_new_anon_rmap() no longer works this way, so just remove the
entire example.
Link: https://lkml.kernel.org/r/20231211162214.2146080-6-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memremap.c | 18 ++++--------------
1 file changed, 4 insertions(+), 14 deletions(-)
--- a/mm/memremap.c~mm-remove-stale-example-from-comment
+++ a/mm/memremap.c
@@ -473,21 +473,11 @@ void free_zone_device_page(struct page *
__ClearPageAnonExclusive(page);
/*
- * When a device managed page is freed, the page->mapping field
+ * When a device managed page is freed, the folio->mapping field
* may still contain a (stale) mapping value. For example, the
- * lower bits of page->mapping may still identify the page as an
- * anonymous page. Ultimately, this entire field is just stale
- * and wrong, and it will cause errors if not cleared. One
- * example is:
- *
- * migrate_vma_pages()
- * migrate_vma_insert_page()
- * page_add_new_anon_rmap()
- * __page_set_anon_rmap()
- * ...checks page->mapping, via PageAnon(page) call,
- * and incorrectly concludes that the page is an
- * anonymous page. Therefore, it incorrectly,
- * silently fails to set up the new anon rmap.
+ * lower bits of folio->mapping may still identify the folio as an
+ * anonymous folio. Ultimately, this entire field is just stale
+ * and wrong, and it will cause errors if not cleared.
*
* For other types of ZONE_DEVICE pages, migration is either
* handled differently or not done at all, so there is no need
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
buffer-return-bool-from-grow_dev_folio.patch
buffer-calculate-block-number-inside-folio_init_buffers.patch
buffer-fix-grow_buffers-for-block-size-page_size.patch
buffer-cast-block-to-loff_t-before-shifting-it.patch
buffer-fix-various-functions-for-block-size-page_size.patch
buffer-handle-large-folios-in-__block_write_begin_int.patch
buffer-fix-more-functions-for-block-size-page_size.patch
mm-convert-ksm_might_need_to_copy-to-work-on-folios.patch
mm-simplify-the-assertions-in-unuse_pte.patch
mm-convert-unuse_pte-to-use-a-folio-throughout.patch
mm-remove-some-calls-to-page_add_new_anon_rmap.patch
mm-remove-stale-example-from-comment.patch
mm-remove-references-to-page_add_new_anon_rmap-in-comments.patch
mm-convert-migrate_vma_insert_page-to-use-a-folio.patch
mm-convert-collapse_huge_page-to-use-a-folio.patch
mm-remove-page_add_new_anon_rmap-and-lru_cache_add_inactive_or_unevictable.patch
