The calculation of the end page index was incorrect, leading to a
regression of 70% when running stress-ng. With this fix, we instead
see a performance improvement of 3%.
Reported-by: kernel test robot <rong.a.chen@xxxxxxxxx>
Tested-by: Xing Zhengjun <zhengjun.xing@xxxxxxxxxxxxxxx>
Fixes: e6e88712e43b ("mm: optimise madvise WILLNEED")
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
mm/madvise.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/madvise.c b/mm/madvise.c
index 9b065d412e5f..e602333f8c0d 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -225,7 +225,7 @@ static void force_shm_swapin_readahead(struct vm_area_struct *vma,
struct address_space *mapping)
{
XA_STATE(xas, &mapping->i_pages, linear_page_index(vma, start));
- pgoff_t end_index = end / PAGE_SIZE;
+ pgoff_t end_index = linear_page_index(vma, end + PAGE_SIZE - 1);
struct page *page;
rcu_read_lock();
--
2.28.0
