The patch titled
Subject: mm/huge_memory: convert split_huge_pages_pid() from follow_page() to folio_walk
has been added to the -mm mm-unstable branch. Its filename is
mm-huge_memory-convert-split_huge_pages_pid-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-huge_memory-convert-split_huge_pages_pid-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
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------------------------------------------------------
From: David Hildenbrand <david@xxxxxxxxxx>
Subject: mm/huge_memory: convert split_huge_pages_pid() from follow_page() to folio_walk
Date: Fri, 2 Aug 2024 17:55:20 +0200
Let's remove yet another follow_page() user. Note that we have to do the
split without holding the PTL, after folio_walk_end(). We don't care
about losing the secretmem check in follow_page().
Link: https://lkml.kernel.org/r/20240802155524.517137-8-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/huge_memory.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
--- a/mm/huge_memory.c~mm-huge_memory-convert-split_huge_pages_pid-from-follow_page-to-folio_walk
+++ a/mm/huge_memory.c
@@ -40,6 +40,7 @@
#include <linux/memory-tiers.h>
#include <linux/compat.h>
#include <linux/pgalloc_tag.h>
+#include <linux/pagewalk.h>
#include <asm/tlb.h>
#include <asm/pgalloc.h>
@@ -3507,7 +3508,7 @@ static int split_huge_pages_pid(int pid,
*/
for (addr = vaddr_start; addr < vaddr_end; addr += PAGE_SIZE) {
struct vm_area_struct *vma = vma_lookup(mm, addr);
- struct page *page;
+ struct folio_walk fw;
struct folio *folio;
if (!vma)
@@ -3519,13 +3520,10 @@ static int split_huge_pages_pid(int pid,
continue;
}
- /* FOLL_DUMP to ignore special (like zero) pages */
- page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP);
-
- if (IS_ERR_OR_NULL(page))
+ folio = folio_walk_start(&fw, vma, addr, 0);
+ if (!folio)
continue;
- folio = page_folio(page);
if (!is_transparent_hugepage(folio))
goto next;
@@ -3544,13 +3542,19 @@ static int split_huge_pages_pid(int pid,
if (!folio_trylock(folio))
goto next;
+ folio_get(folio);
+ folio_walk_end(&fw, vma);
if (!split_folio_to_order(folio, new_order))
split++;
folio_unlock(folio);
-next:
folio_put(folio);
+
+ cond_resched();
+ continue;
+next:
+ folio_walk_end(&fw, vma);
cond_resched();
}
mmap_read_unlock(mm);
_
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
