The 2nd parameter in __page_set_anon_rmap() is only used by
SetPageAnonExclusive(), so there is no need to put
SetPageAnonExclusive() in __page_set_anon_rmap().
Remove SetPageAnonExclusive() from __page_set_anon_rmap() and modify
__page_set_anon_rmap() to __folio_set_anon_rmap().
Since __page_check_anon_rmap() needs a folio, we can directly use
and change it to __folio_check_anon_rmap().
Signed-off-by: Yajun Deng <[email protected]>
---
mm/rmap.c | 54 ++++++++++++++++++++++++++++--------------------------
1 file changed, 28 insertions(+), 26 deletions(-)
diff --git a/mm/rmap.c b/mm/rmap.c
index ba901c416785..8dc71caa208f 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1129,14 +1129,13 @@ void page_move_anon_rmap(struct page *page, struct vm_area_struct *vma)
}
/**
- * __page_set_anon_rmap - set up new anonymous rmap
- * @folio: Folio which contains page.
- * @page: Page to add to rmap.
+ * __folio_set_anon_rmap - set up new anonymous rmap
+ * @folio: Folio to add to rmap.
* @vma: VM area to add page to.
* @address: User virtual address of the mapping
* @exclusive: the page is exclusively owned by the current process
*/
-static void __page_set_anon_rmap(struct folio *folio, struct page *page,
+static void __folio_set_anon_rmap(struct folio *folio,
struct vm_area_struct *vma, unsigned long address, int exclusive)
{
struct anon_vma *anon_vma = vma->anon_vma;
@@ -1144,7 +1143,7 @@ static void __page_set_anon_rmap(struct folio *folio, struct page *page,
BUG_ON(!anon_vma);
if (folio_test_anon(folio))
- goto out;
+ return;
/*
* If the page isn't exclusively mapped into this vma,
@@ -1163,21 +1162,17 @@ static void __page_set_anon_rmap(struct folio *folio, struct page *page,
anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
WRITE_ONCE(folio->mapping, (struct address_space *) anon_vma);
folio->index = linear_page_index(vma, address);
-out:
- if (exclusive)
- SetPageAnonExclusive(page);
}
/**
- * __page_check_anon_rmap - sanity check anonymous rmap addition
- * @page: the page to add the mapping to
+ * __folio_check_anon_rmap - sanity check anonymous rmap addition
+ * @folio: the folio to add the mapping to
* @vma: the vm area in which the mapping is added
* @address: the user virtual address mapped
*/
-static void __page_check_anon_rmap(struct page *page,
+static void __folio_check_anon_rmap(struct folio *folio,
struct vm_area_struct *vma, unsigned long address)
{
- struct folio *folio = page_folio(page);
/*
* The page's anon-rmap details (mapping and index) are guaranteed to
* be set up correctly at this point.
@@ -1191,8 +1186,8 @@ static void __page_check_anon_rmap(struct page *page,
*/
VM_BUG_ON_FOLIO(folio_anon_vma(folio)->root != vma->anon_vma->root,
folio);
- VM_BUG_ON_PAGE(page_to_pgoff(page) != linear_page_index(vma, address),
- page);
+ VM_BUG_ON_FOLIO(folio_pgoff(folio) != linear_page_index(vma, address),
+ folio);
}
/**
@@ -1214,6 +1209,7 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
atomic_t *mapped = &folio->_nr_pages_mapped;
int nr = 0, nr_pmdmapped = 0;
bool compound = flags & RMAP_COMPOUND;
+ bool exclusive = !!(flags & RMAP_EXCLUSIVE);
bool first = true;
/* Is page being mapped by PTE? Is this its first map to be added? */
@@ -1243,7 +1239,7 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
}
}
- VM_BUG_ON_PAGE(!first && (flags & RMAP_EXCLUSIVE), page);
+ VM_BUG_ON_PAGE(!first && exclusive, page);
VM_BUG_ON_PAGE(!first && PageAnonExclusive(page), page);
if (nr_pmdmapped)
@@ -1253,11 +1249,12 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
if (likely(!folio_test_ksm(folio))) {
/* address might be in next vma when migration races vma_merge */
- if (first)
- __page_set_anon_rmap(folio, page, vma, address,
- !!(flags & RMAP_EXCLUSIVE));
- else
- __page_check_anon_rmap(page, vma, address);
+ if (first) {
+ __folio_set_anon_rmap(folio, vma, address, exclusive);
+ if (exclusive)
+ SetPageAnonExclusive(page);
+ } else
+ __folio_check_anon_rmap(folio, vma, address);
}
mlock_vma_folio(folio, vma, compound);
@@ -1297,7 +1294,8 @@ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma,
}
__lruvec_stat_mod_folio(folio, NR_ANON_MAPPED, nr);
- __page_set_anon_rmap(folio, &folio->page, vma, address, 1);
+ __folio_set_anon_rmap(folio, vma, address, 1);
+ SetPageAnonExclusive(&folio->page);
}
/**
@@ -2533,17 +2531,20 @@ void hugepage_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
{
struct folio *folio = page_folio(page);
struct anon_vma *anon_vma = vma->anon_vma;
+ bool exclusive = !!(flags & RMAP_EXCLUSIVE);
int first;
BUG_ON(!folio_test_locked(folio));
BUG_ON(!anon_vma);
/* address might be in next vma when migration races vma_merge */
first = atomic_inc_and_test(&folio->_entire_mapcount);
- VM_BUG_ON_PAGE(!first && (flags & RMAP_EXCLUSIVE), page);
+ VM_BUG_ON_PAGE(!first && exclusive, page);
VM_BUG_ON_PAGE(!first && PageAnonExclusive(page), page);
- if (first)
- __page_set_anon_rmap(folio, page, vma, address,
- !!(flags & RMAP_EXCLUSIVE));
+ if (first) {
+ __folio_set_anon_rmap(folio, vma, address, exclusive);
+ if (exclusive)
+ SetPageAnonExclusive(page);
+ }
}
void hugepage_add_new_anon_rmap(struct folio *folio,
@@ -2553,6 +2554,7 @@ void hugepage_add_new_anon_rmap(struct folio *folio,
/* increment count (starts at -1) */
atomic_set(&folio->_entire_mapcount, 0);
folio_clear_hugetlb_restore_reserve(folio);
- __page_set_anon_rmap(folio, &folio->page, vma, address, 1);
+ __folio_set_anon_rmap(folio, vma, address, 1);
+ SetPageAnonExclusive(&folio->page);
}
#endif /* CONFIG_HUGETLB_PAGE */
--
2.25.1
On 12.04.23 04:18, Yajun Deng wrote:
> The 2nd parameter in __page_set_anon_rmap() is only used by
> SetPageAnonExclusive(), so there is no need to put
> SetPageAnonExclusive() in __page_set_anon_rmap().
>
> Remove SetPageAnonExclusive() from __page_set_anon_rmap() and modify
> __page_set_anon_rmap() to __folio_set_anon_rmap().
>
> Since __page_check_anon_rmap() needs a folio, we can directly use
> and change it to __folio_check_anon_rmap().
>
Leaking the SetPageAnonExclusive() into all callers is not an improvement.
Not convinced we want this patch TBH. Tentative NAK.
--
Thanks,
David / dhildenb
On Wed, Apr 12, 2023 at 10:18:11AM +0800, Yajun Deng wrote:
> The 2nd parameter in __page_set_anon_rmap() is only used by
> SetPageAnonExclusive(), so there is no need to put
> SetPageAnonExclusive() in __page_set_anon_rmap().
>
> Remove SetPageAnonExclusive() from __page_set_anon_rmap() and modify
> __page_set_anon_rmap() to __folio_set_anon_rmap().
>
> Since __page_check_anon_rmap() needs a folio, we can directly use
> and change it to __folio_check_anon_rmap().
I do not think this is an improvement.