Hi Miaohe,
On Tue, Aug 30, 2022 at 08:36:00PM +0800, Miaohe Lin wrote:
> It's more recommended to use __PageMovable() to detect non-lru movable
> pages. We can avoid bumping page refcnt via isolate_movable_page() for
> the isolated lru pages. Also if pages become PageLRU just after they're
> checked but before trying to isolate them, isolate_lru_page() will be
> called to do the right work.
Good point, non-lru movable page is currently handled by isolate_lru_page(),
which always fails. This means that we lost the chance of soft-offlining
for any non-lru movable page. So this patch improves the situation.
>
> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
> ---
> mm/memory-failure.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index a923a6dde871..3966fa6abe03 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -2404,7 +2404,7 @@ EXPORT_SYMBOL(unpoison_memory);
> static bool isolate_page(struct page *page, struct list_head *pagelist)
> {
> bool isolated = false;
> - bool lru = PageLRU(page);
> + bool lru = !__PageMovable(page);
It seems that PAGE_MAPPING_MOVABLE is not set for hugetlb pages, so
lru becomes true for them. Then, if isolate_hugetlb() succeeds,
inc_node_page_state() is called for hugetlb pages, maybe that's not expected.
>
> if (PageHuge(page)) {
> isolated = !isolate_hugetlb(page, pagelist);
} else {
if (lru)
isolated = !isolate_lru_page(page);
else
isolated = !isolate_movable_page(page, ISOLATE_UNEVICTABLE);
if (isolated)
list_add(&page->lru, pagelist);
}
if (isolated && lru)
inc_node_page_state(page, NR_ISOLATED_ANON +
page_is_file_lru(page));
so, how about moving this if block into the above else block?
Then, the automatic variable lru can be moved into the else block.
Thanks,
Naoya Horiguchi
