On 04.06.24 06:24, alexs@xxxxxxxxxx wrote:
From: "Alex Shi (tencent)" <alexs@xxxxxxxxxx>
Let's check the whole folio for contents change, don't count it if the
folio changed.
Signed-off-by: Alex Shi (tencent) <alexs@xxxxxxxxxx>
---
mm/ksm.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/mm/ksm.c b/mm/ksm.c
index b9c04ce677b9..dc2b5e6a9659 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1258,11 +1258,13 @@ static int unmerge_and_remove_all_rmap_items(void)
}
#endif /* CONFIG_SYSFS */
-static u32 calc_checksum(struct page *page)
+static u32 calc_checksum(struct folio *folio)
{
u32 checksum;
- void *addr = kmap_local_page(page);
- checksum = xxhash(addr, PAGE_SIZE, 0);
+ int nr = folio_nr_pages(folio);
+ void *addr = kmap_local_page(folio_page(folio, 0));
+
+ checksum = xxhash(addr, nr * PAGE_SIZE, 0);
kunmap_local(addr);
return checksum;
}
@@ -2369,7 +2371,7 @@ static void cmp_and_merge_page(struct page *page, struct ksm_rmap_item *rmap_ite
* don't want to insert it in the unstable tree, and we don't want
* to waste our time searching for something identical to it there.
*/
- checksum = calc_checksum(page);
+ checksum = calc_checksum(folio);
So for a large folio you suddenly checksum more than a single page?
That's wrong.
Or am I missing something?
--
Cheers,
David / dhildenb
