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authorMatthew Wilcox (Oracle) <willy@infradead.org>2023-12-11 16:22:06 +0000
committerAndrew Morton <akpm@linux-foundation.org>2023-12-29 11:58:25 -0800
commit96db66d9c8f3c1547325af01b1f328b85d6ee1b9 (patch)
tree694fc3c38bee2bf254994c55ec2ddf3fea6bec31
parenta2bf6a9ca80532b75f8f8b6a1cd75ef7e5150576 (diff)
mm: convert ksm_might_need_to_copy() to work on folios
Patch series "Finish two folio conversions". Most callers of page_add_new_anon_rmap() and lru_cache_add_inactive_or_unevictable() have been converted to their folio equivalents, but there are still a few stragglers. There's a bit of preparatory work in ksm and unuse_pte(), but after that it's pretty mechanical. This patch (of 9): Accept a folio as an argument and return a folio result. Removes a call to compound_head() in do_swap_page(), and prevents folio & page from getting out of sync in unuse_pte(). Reviewed-by: David Hildenbrand <david@redhat.com> [willy@infradead.org: fix smatch warning] Link: https://lkml.kernel.org/r/ZXnPtblC6A1IkyAB@casper.infradead.org [david@redhat.com: only adjust the page if the folio changed] Link: https://lkml.kernel.org/r/6a8f2110-fa91-4c10-9eae-88315309a6e3@redhat.com Link: https://lkml.kernel.org/r/20231211162214.2146080-1-willy@infradead.org Link: https://lkml.kernel.org/r/20231211162214.2146080-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--include/linux/ksm.h6
-rw-r--r--mm/ksm.c21
-rw-r--r--mm/memory.c11
-rw-r--r--mm/swapfile.c8
4 files changed, 26 insertions, 20 deletions
diff --git a/include/linux/ksm.h b/include/linux/ksm.h
index 4643d5244e77..401348e9f92b 100644
--- a/include/linux/ksm.h
+++ b/include/linux/ksm.h
@@ -76,7 +76,7 @@ static inline void ksm_exit(struct mm_struct *mm)
* We'd like to make this conditional on vma->vm_flags & VM_MERGEABLE,
* but what if the vma was unmerged while the page was swapped out?
*/
-struct page *ksm_might_need_to_copy(struct page *page,
+struct folio *ksm_might_need_to_copy(struct folio *folio,
struct vm_area_struct *vma, unsigned long addr);
void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc);
@@ -129,10 +129,10 @@ static inline int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
return 0;
}
-static inline struct page *ksm_might_need_to_copy(struct page *page,
+static inline struct folio *ksm_might_need_to_copy(struct folio *folio,
struct vm_area_struct *vma, unsigned long addr)
{
- return page;
+ return folio;
}
static inline void rmap_walk_ksm(struct folio *folio,
diff --git a/mm/ksm.c b/mm/ksm.c
index c0e1995fb444..e2ce850c2739 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -2873,30 +2873,30 @@ void __ksm_exit(struct mm_struct *mm)
trace_ksm_exit(mm);
}
-struct page *ksm_might_need_to_copy(struct page *page,
+struct folio *ksm_might_need_to_copy(struct folio *folio,
struct vm_area_struct *vma, unsigned long addr)
{
- struct folio *folio = page_folio(page);
+ struct page *page = folio_page(folio, 0);
struct anon_vma *anon_vma = folio_anon_vma(folio);
struct folio *new_folio;
if (folio_test_large(folio))
- return page;
+ return folio;
if (folio_test_ksm(folio)) {
if (folio_stable_node(folio) &&
!(ksm_run & KSM_RUN_UNMERGE))
- return page; /* no need to copy it */
+ return folio; /* no need to copy it */
} else if (!anon_vma) {
- return page; /* no need to copy it */
+ return folio; /* no need to copy it */
} else if (folio->index == linear_page_index(vma, addr) &&
anon_vma->root == vma->anon_vma->root) {
- return page; /* still no need to copy it */
+ return folio; /* still no need to copy it */
}
if (PageHWPoison(page))
return ERR_PTR(-EHWPOISON);
if (!folio_test_uptodate(folio))
- return page; /* let do_swap_page report the error */
+ return folio; /* let do_swap_page report the error */
new_folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, vma, addr, false);
if (new_folio &&
@@ -2905,9 +2905,10 @@ struct page *ksm_might_need_to_copy(struct page *page,
new_folio = NULL;
}
if (new_folio) {
- if (copy_mc_user_highpage(&new_folio->page, page, addr, vma)) {
+ if (copy_mc_user_highpage(folio_page(new_folio, 0), page,
+ addr, vma)) {
folio_put(new_folio);
- memory_failure_queue(page_to_pfn(page), 0);
+ memory_failure_queue(folio_pfn(folio), 0);
return ERR_PTR(-EHWPOISON);
}
folio_set_dirty(new_folio);
@@ -2918,7 +2919,7 @@ struct page *ksm_might_need_to_copy(struct page *page,
#endif
}
- return new_folio ? &new_folio->page : NULL;
+ return new_folio;
}
void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc)
diff --git a/mm/memory.c b/mm/memory.c
index b9cc56a75f4b..7649cb9eb7f5 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3942,15 +3942,18 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
* page->index of !PageKSM() pages would be nonlinear inside the
* anon VMA -- PageKSM() is lost on actual swapout.
*/
- page = ksm_might_need_to_copy(page, vma, vmf->address);
- if (unlikely(!page)) {
+ folio = ksm_might_need_to_copy(folio, vma, vmf->address);
+ if (unlikely(!folio)) {
ret = VM_FAULT_OOM;
+ folio = swapcache;
goto out_page;
- } else if (unlikely(PTR_ERR(page) == -EHWPOISON)) {
+ } else if (unlikely(folio == ERR_PTR(-EHWPOISON))) {
ret = VM_FAULT_HWPOISON;
+ folio = swapcache;
goto out_page;
}
- folio = page_folio(page);
+ if (folio != swapcache)
+ page = folio_page(folio, 0);
/*
* If we want to map a page that's in the swapcache writable, we
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 8be70912e298..0371b7b3cd27 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1749,11 +1749,13 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
int ret = 1;
swapcache = page;
- page = ksm_might_need_to_copy(page, vma, addr);
- if (unlikely(!page))
+ folio = ksm_might_need_to_copy(folio, vma, addr);
+ if (unlikely(!folio))
return -ENOMEM;
- else if (unlikely(PTR_ERR(page) == -EHWPOISON))
+ else if (unlikely(folio == ERR_PTR(-EHWPOISON)))
hwpoisoned = true;
+ else
+ page = folio_file_page(folio, swp_offset(entry));
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
if (unlikely(!pte || !pte_same_as_swp(ptep_get(pte),