On Thu, Aug 18, 2022 at 09:00:16PM +0800, Miaohe Lin wrote:
> For reserved pages, HWPoison flag will be set without increasing the page
> refcnt. So we shouldn't even try to unpoison these pages and thus decrease
> the page refcnt unexpectly. Add a PageReserved() check to filter this case
> out and remove the below unneeded zero page (zero page is reserved) check.
>
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Looks good to me, thank you.
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
> ---
> mm/memory-failure.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 5f9615a86296..c831c41bb092 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -2355,7 +2355,7 @@ int unpoison_memory(unsigned long pfn)
> goto unlock_mutex;
> }
>
> - if (PageSlab(page) || PageTable(page))
> + if (PageSlab(page) || PageTable(page) || PageReserved(page))
> goto unlock_mutex;
>
> ret = get_hwpoison_page(p, MF_UNPOISON);
> @@ -2386,7 +2386,7 @@ int unpoison_memory(unsigned long pfn)
> freeit = !!TestClearPageHWPoison(p);
>
> put_page(page);
> - if (freeit && !(pfn == my_zero_pfn(0) && page_count(p) == 1)) {
> + if (freeit) {
> put_page(page);
> ret = 0;
> }
> --
> 2.23.0