2015-08-07 10:17:03

by Wanpeng Li

Subject: [PATCH v2 2/2] mm/hwpoison: fix fail isolate hugetlbfs page w/ refcount held

Hugetlbfs pages will get a refcount in get_any_page() or madvise_hwpoison()
if soft offline through madvise. The refcount which held by soft offline
path should be released if fail to isolate hugetlbfs pages. This patch fix
it by reducing a refcount for both isolate successfully and failure.

Cc: <[email protected]> # 3.9+
Signed-off-by: Wanpeng Li <[email protected]>
---
mm/memory-failure.c | 13 ++++++-------
1 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 001f1ba..8077b1c 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1557,13 +1557,12 @@ static int soft_offline_huge_page(struct page *page, int flags)
unlock_page(hpage);

ret = isolate_huge_page(hpage, &pagelist);
- if (ret) {
- /*
- * get_any_page() and isolate_huge_page() takes a refcount each,
- * so need to drop one here.
- */
- put_page(hpage);
- } else {
+ /*
+ * get_any_page() and isolate_huge_page() takes a refcount each,
+ * so need to drop one here.
+ */
+ put_page(hpage);
+ if (!ret) {
pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
return -EBUSY;
}
--
1.7.1

2015-08-10 01:06:55

by Naoya Horiguchi

Subject: Re: [PATCH v2 2/2] mm/hwpoison: fix fail isolate hugetlbfs page w/ refcount held

On Fri, Aug 07, 2015 at 06:16:42PM +0800, Wanpeng Li wrote:
> Hugetlbfs pages will get a refcount in get_any_page() or madvise_hwpoison()
> if soft offline through madvise. The refcount which held by soft offline
> path should be released if fail to isolate hugetlbfs pages. This patch fix
> it by reducing a refcount for both isolate successfully and failure.
>
> Cc: <[email protected]> # 3.9+
> Signed-off-by: Wanpeng Li <[email protected]>

Acked-by: Naoya Horiguchi <[email protected]>

> ---
> mm/memory-failure.c | 13 ++++++-------
> 1 files changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 001f1ba..8077b1c 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1557,13 +1557,12 @@ static int soft_offline_huge_page(struct page *page, int flags)
> unlock_page(hpage);
>
> ret = isolate_huge_page(hpage, &pagelist);
> - if (ret) {
> - /*
> - * get_any_page() and isolate_huge_page() takes a refcount each,
> - * so need to drop one here.
> - */
> - put_page(hpage);
> - } else {
> + /*
> + * get_any_page() and isolate_huge_page() takes a refcount each,
> + * so need to drop one here.
> + */
> + put_page(hpage);
> + if (!ret) {
> pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
> return -EBUSY;
> }
> --
> 1.7.1
> -