| Message ID | 20220312074613.4798-4-linmiaohe@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | A few fixup patches for memory failure | expand |
On Sat, Mar 12, 2022 at 03:46:13PM +0800, Miaohe Lin wrote: > We can not really handle non-LRU movable pages in memory failure. Typically > they are balloon, zsmalloc, etc. Assuming we run into a base (4K) non-LRU > movable page, we could reach as far as identify_page_state(), it should not > fall into any category except me_unknown. For the non-LRU compound movable > pages, they could be taken for transhuge pages but it's unexpected to split > non-LRU movable pages using split_huge_page_to_list in memory_failure. So > we could just simply make non-LRU movable pages unhandlable to avoid these > possible nasty cases. > > Suggested-by: Yang Shi <shy828301@gmail.com> > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Looks good to me. Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
On Fri, Mar 11, 2022 at 11:47 PM Miaohe Lin <linmiaohe@huawei.com> wrote: > > We can not really handle non-LRU movable pages in memory failure. Typically > they are balloon, zsmalloc, etc. Assuming we run into a base (4K) non-LRU > movable page, we could reach as far as identify_page_state(), it should not > fall into any category except me_unknown. For the non-LRU compound movable > pages, they could be taken for transhuge pages but it's unexpected to split > non-LRU movable pages using split_huge_page_to_list in memory_failure. So > we could just simply make non-LRU movable pages unhandlable to avoid these > possible nasty cases. > > Suggested-by: Yang Shi <shy828301@gmail.com> > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Yang Shi <shy828301@gmail.com> > --- > mm/memory-failure.c | 20 +++++++++++++------- > 1 file changed, 13 insertions(+), 7 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 2ff7dd2078c4..ba621c6823ed 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1177,12 +1177,18 @@ void ClearPageHWPoisonTakenOff(struct page *page) > * does not return true for hugetlb or device memory pages, so it's assumed > * to be called only in the context where we never have such pages. > */ > -static inline bool HWPoisonHandlable(struct page *page) > +static inline bool HWPoisonHandlable(struct page *page, unsigned long flags) > { > - return PageLRU(page) || __PageMovable(page) || is_free_buddy_page(page); > + bool movable = false; > + > + /* Soft offline could mirgate non-LRU movable pages */ > + if ((flags & MF_SOFT_OFFLINE) && __PageMovable(page)) > + movable = true; > + > + return movable || PageLRU(page) || is_free_buddy_page(page); > } > > -static int __get_hwpoison_page(struct page *page) > +static int __get_hwpoison_page(struct page *page, unsigned long flags) > { > struct page *head = compound_head(page); > int ret = 0; > @@ -1197,7 +1203,7 @@ static int __get_hwpoison_page(struct page *page) > * for any unsupported type of page in order to reduce the risk of > * unexpected races caused by taking a page refcount. > */ > - if (!HWPoisonHandlable(head)) > + if (!HWPoisonHandlable(head, flags)) > return -EBUSY; > > if (get_page_unless_zero(head)) { > @@ -1222,7 +1228,7 @@ static int get_any_page(struct page *p, unsigned long flags) > > try_again: > if (!count_increased) { > - ret = __get_hwpoison_page(p); > + ret = __get_hwpoison_page(p, flags); > if (!ret) { > if (page_count(p)) { > /* We raced with an allocation, retry. */ > @@ -1250,7 +1256,7 @@ static int get_any_page(struct page *p, unsigned long flags) > } > } > > - if (PageHuge(p) || HWPoisonHandlable(p)) { > + if (PageHuge(p) || HWPoisonHandlable(p, flags)) { > ret = 1; > } else { > /* > @@ -2308,7 +2314,7 @@ int soft_offline_page(unsigned long pfn, int flags) > > retry: > get_online_mems(); > - ret = get_hwpoison_page(page, flags); > + ret = get_hwpoison_page(page, flags | MF_SOFT_OFFLINE); > put_online_mems(); > > if (ret > 0) { > -- > 2.23.0 >
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 2ff7dd2078c4..ba621c6823ed 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1177,12 +1177,18 @@ void ClearPageHWPoisonTakenOff(struct page *page) * does not return true for hugetlb or device memory pages, so it's assumed * to be called only in the context where we never have such pages. */ -static inline bool HWPoisonHandlable(struct page *page) +static inline bool HWPoisonHandlable(struct page *page, unsigned long flags) { - return PageLRU(page) || __PageMovable(page) || is_free_buddy_page(page); + bool movable = false; + + /* Soft offline could mirgate non-LRU movable pages */ + if ((flags & MF_SOFT_OFFLINE) && __PageMovable(page)) + movable = true; + + return movable || PageLRU(page) || is_free_buddy_page(page); } -static int __get_hwpoison_page(struct page *page) +static int __get_hwpoison_page(struct page *page, unsigned long flags) { struct page *head = compound_head(page); int ret = 0; @@ -1197,7 +1203,7 @@ static int __get_hwpoison_page(struct page *page) * for any unsupported type of page in order to reduce the risk of * unexpected races caused by taking a page refcount. */ - if (!HWPoisonHandlable(head)) + if (!HWPoisonHandlable(head, flags)) return -EBUSY; if (get_page_unless_zero(head)) { @@ -1222,7 +1228,7 @@ static int get_any_page(struct page *p, unsigned long flags) try_again: if (!count_increased) { - ret = __get_hwpoison_page(p); + ret = __get_hwpoison_page(p, flags); if (!ret) { if (page_count(p)) { /* We raced with an allocation, retry. */ @@ -1250,7 +1256,7 @@ static int get_any_page(struct page *p, unsigned long flags) } } - if (PageHuge(p) || HWPoisonHandlable(p)) { + if (PageHuge(p) || HWPoisonHandlable(p, flags)) { ret = 1; } else { /* @@ -2308,7 +2314,7 @@ int soft_offline_page(unsigned long pfn, int flags) retry: get_online_mems(); - ret = get_hwpoison_page(page, flags); + ret = get_hwpoison_page(page, flags | MF_SOFT_OFFLINE); put_online_mems(); if (ret > 0) {
We can not really handle non-LRU movable pages in memory failure. Typically they are balloon, zsmalloc, etc. Assuming we run into a base (4K) non-LRU movable page, we could reach as far as identify_page_state(), it should not fall into any category except me_unknown. For the non-LRU compound movable pages, they could be taken for transhuge pages but it's unexpected to split non-LRU movable pages using split_huge_page_to_list in memory_failure. So we could just simply make non-LRU movable pages unhandlable to avoid these possible nasty cases. Suggested-by: Yang Shi <shy828301@gmail.com> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- mm/memory-failure.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-)