The patch titled
Subject: mm/ksm: convert get_mergeable_page() from follow_page() to folio_walk
has been added to the -mm mm-unstable branch. Its filename is
mm-ksm-convert-get_mergeable_page-from-follow_page-to-folio_walk.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-ksm-convert-get_mergeable_page-from-follow_page-to-folio_walk.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: David Hildenbrand <david@xxxxxxxxxx>
Subject: mm/ksm: convert get_mergeable_page() from follow_page() to folio_walk
Date: Fri, 2 Aug 2024 17:55:18 +0200
Let's use folio_walk instead, for example avoiding taking temporary folio
references if the folio does not even apply and getting rid of one more
follow_page() user.
Note that zeropages obviously don't apply: old code could just have
specified FOLL_DUMP. Anon folios are never secretmem, so we don't care
about losing the check in follow_page().
Link: https://lkml.kernel.org/r/20240802155524.517137-6-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
Cc: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Janosch Frank <frankja@xxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/ksm.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)
--- a/mm/ksm.c~mm-ksm-convert-get_mergeable_page-from-follow_page-to-folio_walk
+++ a/mm/ksm.c
@@ -767,26 +767,28 @@ static struct page *get_mergeable_page(s
struct mm_struct *mm = rmap_item->mm;
unsigned long addr = rmap_item->address;
struct vm_area_struct *vma;
- struct page *page;
+ struct page *page = NULL;
+ struct folio_walk fw;
+ struct folio *folio;
mmap_read_lock(mm);
vma = find_mergeable_vma(mm, addr);
if (!vma)
goto out;
- page = follow_page(vma, addr, FOLL_GET);
- if (IS_ERR_OR_NULL(page))
- goto out;
- if (is_zone_device_page(page))
- goto out_putpage;
- if (PageAnon(page)) {
+ folio = folio_walk_start(&fw, vma, addr, 0);
+ if (folio) {
+ if (!folio_is_zone_device(folio) &&
+ folio_test_anon(folio)) {
+ folio_get(folio);
+ page = fw.page;
+ }
+ folio_walk_end(&fw, vma);
+ }
+out:
+ if (page) {
flush_anon_page(vma, page, addr);
flush_dcache_page(page);
- } else {
-out_putpage:
- put_page(page);
-out:
- page = NULL;
}
mmap_read_unlock(mm);
return page;
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
mm-turn-use_split_pte_ptlocks-use_split_pte_ptlocks-into-kconfig-options.patch
mm-hugetlb-enforce-that-pmd-pt-sharing-has-split-pmd-pt-locks.patch
powerpc-8xx-document-and-enforce-that-split-pt-locks-are-not-used.patch
mm-simplify-arch_make_folio_accessible.patch
mm-gup-convert-to-arch_make_folio_accessible.patch
s390-uv-drop-arch_make_page_accessible.patch
mm-hugetlb-remove-hugetlb_follow_page_mask-leftover.patch
mm-rmap-cleanup-partially-mapped-handling-in-__folio_remove_rmap.patch
mm-clarify-folio_likely_mapped_shared-documentation-for-ksm-folios.patch
mm-provide-vm_normal_pagefolio_pmd-with-config_pgtable_has_huge_leaves.patch
mm-pagewalk-introduce-folio_walk_start-folio_walk_end.patch
mm-migrate-convert-do_pages_stat_array-from-follow_page-to-folio_walk.patch
mm-migrate-convert-add_page_for_migration-from-follow_page-to-folio_walk.patch
mm-ksm-convert-get_mergeable_page-from-follow_page-to-folio_walk.patch
mm-ksm-convert-scan_get_next_rmap_item-from-follow_page-to-folio_walk.patch
mm-huge_memory-convert-split_huge_pages_pid-from-follow_page-to-folio_walk.patch
s390-uv-convert-gmap_destroy_page-from-follow_page-to-folio_walk.patch
s390-mm-fault-convert-do_secure_storage_access-from-follow_page-to-folio_walk.patch
mm-remove-follow_page.patch
mm-ksm-convert-break_ksm-from-walk_page_range_vma-to-folio_walk.patch
