Hello,
On Thu, Jan 19, 2017 at 10:59:03PM +0800, ys...@foxmail.com wrote:
> From: Yisheng Xie <xieyishe...@huawei.com>
>
> This patch is to extends soft offlining framework to support
> non-lru page, which already support migration after
> commit bda807d44454 ("mm: migrate: support non-lru movable page
> migration")
>
> When memory corrected errors occur on a non-lru movable page,
> we can choose to stop using it by migrating data onto another
> page and disable the original (maybe half-broken) one.
>
> Signed-off-by: Yisheng Xie <xieyishe...@huawei.com>
> Suggested-by: Michal Hocko <mho...@kernel.org>
> ---
> v2:
> delete function soft_offline_movable_page() and hanle non-lru movable
> page in __soft_offline_page() as Michal Hocko suggested.
>
> Any comment is more than welcome.
>
> mm/memory-failure.c | 27 +++++++++++++++------------
> 1 file changed, 15 insertions(+), 12 deletions(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index f283c7e..74be9e1 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1527,7 +1527,8 @@ static int get_any_page(struct page *page, unsigned
> long pfn, int flags)
> {
> int ret = __get_any_page(page, pfn, flags);
>
> - if (ret == 1 && !PageHuge(page) && !PageLRU(page)) {
> + if (ret == 1 && !PageHuge(page) &&
> + !PageLRU(page) && !__PageMovable(page)) {
__PageMovable without holding page_lock could be raced so need to check
if it's okay to miss some of pages offlining by the race.
When I read description of soft_offline_page, it seems to be okay.
Just wanted double check. :)
> /*
> * Try to free it.
> */
> @@ -1609,7 +1610,7 @@ static int soft_offline_huge_page(struct page *page,
> int flags)
>
> static int __soft_offline_page(struct page *page, int flags)
> {
> - int ret;
> + int ret = -1;
> unsigned long pfn = page_to_pfn(page);
>
> /*
> @@ -1619,7 +1620,8 @@ static int __soft_offline_page(struct page *page, int
> flags)
> * so there's no race between soft_offline_page() and memory_failure().
> */
> lock_page(page);
> - wait_on_page_writeback(page);
> + if (PageLRU(page))
> + wait_on_page_writeback(page);
I doubt we need to add such limitation(i.e., Only LRU pages could be
write-backed).
Do you have some reason to add that code?
> if (PageHWPoison(page)) {
> unlock_page(page);
> put_hwpoison_page(page);
> @@ -1630,7 +1632,8 @@ static int __soft_offline_page(struct page *page, int
> flags)
> * Try to invalidate first. This should work for
> * non dirty unmapped page cache pages.
> */
> - ret = invalidate_inode_page(page);
> + if (PageLRU(page))
> + ret = invalidate_inode_page(page);
Ditto.
> unlock_page(page);
> /*
> * RED-PEN would be better to keep it isolated here, but we
> @@ -1649,7 +1652,10 @@ static int __soft_offline_page(struct page *page, int
> flags)
> * Try to migrate to a new page instead. migrate.c
> * handles a large number of cases for us.
> */
> - ret = isolate_lru_page(page);
> + if (PageLRU(page))
> + ret = isolate_lru_page(page);
> + else
> + ret = !isolate_movable_page(page, ISOLATE_UNEVICTABLE);
> /*
> * Drop page reference which is came from get_any_page()
> * successful isolate_lru_page() already took another one.
> @@ -1657,18 +1663,15 @@ static int __soft_offline_page(struct page *page, int
> flags)
> put_hwpoison_page(page);
> if (!ret) {
> LIST_HEAD(pagelist);
> - inc_node_page_state(page, NR_ISOLATED_ANON +
> + if (PageLRU(page))
isolate_lru_page removes PG_lru so this check will be false. Namely, happens
isolated count mismatch happens.
> + inc_node_page_state(page, NR_ISOLATED_ANON +
> page_is_file_cache(page));
> list_add(&page->lru, &pagelist);
> ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
> MIGRATE_SYNC, MR_MEMORY_FAILURE);
> if (ret) {
> - if (!list_empty(&pagelist)) {
> - list_del(&page->lru);
> - dec_node_page_state(page, NR_ISOLATED_ANON +
> - page_is_file_cache(page));
> - putback_lru_page(page);
> - }
> + if (!list_empty(&pagelist))
> + putback_movable_pages(&pagelist);
>
> pr_info("soft offline: %#lx: migration failed %d, type
> %lx\n",
> pfn, ret, page->flags);
> --
> 1.9.1
>
>
>
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