The patch titled
Subject: mm: ksm: use more folio api in ksm_might_need_to_copy()
has been added to the -mm mm-unstable branch. Its filename is
mm-ksm-use-more-folio-api-in-ksm_might_need_to_copy.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-ksm-use-more-folio-api-in-ksm_might_need_to_copy.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: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Subject: mm: ksm: use more folio api in ksm_might_need_to_copy()
Date: Sat, 18 Nov 2023 10:32:28 +0800
Patch series "mm: cleanup and use more folio in page fault", v3.
Rename page_copy_prealloc() to folio_prealloc(), which is used by more
functions, also do more folio conversion in page fault.
This patch (of 5):
Since ksm only support normal page, no swapout/in for ksm large folio too,
add large folio check in ksm_might_need_to_copy(), also convert
page->index to folio->index as page->index is going away.
Then convert ksm_might_need_to_copy() to use more folio api to save nine
compound_head() calls, short 'address' to reduce max-line-length.
Link: https://lkml.kernel.org/r/20231118023232.1409103-1-wangkefeng.wang@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20231118023232.1409103-2-wangkefeng.wang@xxxxxxxxxx
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Cc: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/ksm.h | 4 ++--
mm/ksm.c | 39 +++++++++++++++++++++------------------
2 files changed, 23 insertions(+), 20 deletions(-)
--- a/include/linux/ksm.h~mm-ksm-use-more-folio-api-in-ksm_might_need_to_copy
+++ a/include/linux/ksm.h
@@ -77,7 +77,7 @@ static inline void ksm_exit(struct mm_st
* but what if the vma was unmerged while the page was swapped out?
*/
struct page *ksm_might_need_to_copy(struct page *page,
- struct vm_area_struct *vma, unsigned long address);
+ struct vm_area_struct *vma, unsigned long addr);
void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc);
void folio_migrate_ksm(struct folio *newfolio, struct folio *folio);
@@ -130,7 +130,7 @@ static inline int ksm_madvise(struct vm_
}
static inline struct page *ksm_might_need_to_copy(struct page *page,
- struct vm_area_struct *vma, unsigned long address)
+ struct vm_area_struct *vma, unsigned long addr)
{
return page;
}
--- a/mm/ksm.c~mm-ksm-use-more-folio-api-in-ksm_might_need_to_copy
+++ a/mm/ksm.c
@@ -2876,48 +2876,51 @@ void __ksm_exit(struct mm_struct *mm)
}
struct page *ksm_might_need_to_copy(struct page *page,
- struct vm_area_struct *vma, unsigned long address)
+ struct vm_area_struct *vma, unsigned long addr)
{
struct folio *folio = page_folio(page);
struct anon_vma *anon_vma = folio_anon_vma(folio);
- struct page *new_page;
+ struct folio *new_folio;
- if (PageKsm(page)) {
- if (page_stable_node(page) &&
+ if (folio_test_large(folio))
+ return page;
+
+ if (folio_test_ksm(folio)) {
+ if (folio_stable_node(folio) &&
!(ksm_run & KSM_RUN_UNMERGE))
return page; /* no need to copy it */
} else if (!anon_vma) {
return page; /* no need to copy it */
- } else if (page->index == linear_page_index(vma, address) &&
+ } else if (folio->index == linear_page_index(vma, addr) &&
anon_vma->root == vma->anon_vma->root) {
return page; /* still no need to copy it */
}
if (PageHWPoison(page))
return ERR_PTR(-EHWPOISON);
- if (!PageUptodate(page))
+ if (!folio_test_uptodate(folio))
return page; /* let do_swap_page report the error */
- new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
- if (new_page &&
- mem_cgroup_charge(page_folio(new_page), vma->vm_mm, GFP_KERNEL)) {
- put_page(new_page);
- new_page = NULL;
+ new_folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, vma, addr, false);
+ if (new_folio &&
+ mem_cgroup_charge(new_folio, vma->vm_mm, GFP_KERNEL)) {
+ folio_put(new_folio);
+ new_folio = NULL;
}
- if (new_page) {
- if (copy_mc_user_highpage(new_page, page, address, vma)) {
- put_page(new_page);
+ if (new_folio) {
+ if (copy_mc_user_highpage(&new_folio->page, page, addr, vma)) {
+ folio_put(new_folio);
memory_failure_queue(page_to_pfn(page), 0);
return ERR_PTR(-EHWPOISON);
}
- SetPageDirty(new_page);
- __SetPageUptodate(new_page);
- __SetPageLocked(new_page);
+ folio_set_dirty(new_folio);
+ __folio_mark_uptodate(new_folio);
+ __folio_set_locked(new_folio);
#ifdef CONFIG_SWAP
count_vm_event(KSM_SWPIN_COPY);
#endif
}
- return new_page;
+ return new_folio ? &new_folio->page : NULL;
}
void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc)
_
Patches currently in -mm which might be from wangkefeng.wang@xxxxxxxxxx are
mm-ksm-use-more-folio-api-in-ksm_might_need_to_copy.patch
mm-memory-use-a-folio-in-validate_page_before_insert.patch
mm-memory-rename-page_copy_prealloc-to-folio_prealloc.patch
mm-memory-use-a-folio-in-do_cow_fault.patch
mm-memory-use-folio_prealloc-in-wp_page_copy.patch
