On Mon, May 17, 2021 at 02:59:03PM +0200, Oscar Salvador wrote:
> On Mon, May 17, 2021 at 01:54:01PM +0900, Naoya Horiguchi wrote:
> > static int __get_hwpoison_page(struct page *page)
> > {
> > struct page *head = compound_head(page);
> > @@ -1098,7 +1091,9 @@ static int __get_hwpoison_page(struct page *page)
> >
> > #ifdef CONFIG_HUGETLB_PAGE
> > spin_lock(&hugetlb_lock);
> > - if (PageHuge(head) && (HPageFreed(head) || HPageMigratable(head)))
> > + if (!PageHuge(head))
> > + ret = -EBUSY;
>
> Unless I'm missing something, we will be returning -EBUSY for any non-hugetlb
> page, which is not right.
(sigh, hard to say why I wrote this, really sorry)
> I think what you want is to return -EBUSY in case the page is a hugetlb page
> but we cannot grab a refcount because the page is in a floating state, meaning
> !HPageFreed && !HPageMigratable.
>
> Right?
Totally right, so the below should what's wanted.
spin_lock(&hugetlb_lock);
if (PageHuge(head))
if (!HPageFreed(head) && !HPageMigratable(head))
ret = -EBUSY;
else
ret = get_page_unless_zero(head);
spin_unlock(&hugetlb_lock);
- Naoya
