2022-08-04 12:02:22

by 罗飞

Subject: [PATCH] mm, hwpoison, hugetlb: Check hugetlb head page hwpoison flag when unpoison page

When software-poison a huge page, if dissolve_free_huge_page() failed,
the huge page will be added to hugepage_freelists. In this case, the
head page will hold the hwpoison flag, but the real poisoned tail page
hwpoison flag is not set, this will cause unpoison_memory() fail to
unpoison the previously poisoned page.

So add a check on hugetlb head page, and also need to ensure the
previously poisoned tail page in huge page raw_hwp_list.

Signed-off-by: luofei <[email protected]>
---
mm/memory-failure.c | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 14439806b5ef..fc571b0ceb9d 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2293,6 +2293,28 @@ core_initcall(memory_failure_init);
pr_info(fmt, pfn); \
})

+static bool hugetlb_page_head_poison(struct page *hpage, struct page *page)
+{
+ struct llist_head *head;
+ struct llist_node *t, *tnode;
+ struct raw_hwp_page *p;
+
+ if (PageHuge(page) && PageHWPoison(hpage) && HPageFreed(hpage))
+ return false;
+
+ if (HPageRawHwpUnreliable(hpage))
+ return false;
+
+ head = raw_hwp_list_head(hpage);
+ llist_for_each_safe(tnode, t, head->first) {
+ p = container_of(tnode, struct raw_hwp_page, node);
+ if (p->page == page)
+ return true;
+ }
+
+ return false;
+}
+
/**
* unpoison_memory - Unpoison a previously poisoned page
* @pfn: Page number of the to be unpoisoned page
@@ -2330,7 +2352,7 @@ int unpoison_memory(unsigned long pfn)
goto unlock_mutex;
}

- if (!PageHWPoison(p)) {
+ if (!PageHWPoison(p) && !hugetlb_page_head_poison(page, p)) {
unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n",
pfn, &unpoison_rs);
goto unlock_mutex;
--
2.27.0

2022-08-04 12:57:55

by 罗飞

Subject: 答复: [PATCH] mm, hwpoison, hugetlb: Check hu getlb head page hwpoison flag when unpoison p age

Sorry, wrong patch, please ignore this email.
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????ʱ??: 2022??8??4?? 19:33:08
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????: [email protected]; [email protected]; [email protected]; ?޷?
????: [PATCH] mm, hwpoison, hugetlb: Check hugetlb head page hwpoison flag when unpoison page

When software-poison a huge page, if dissolve_free_huge_page() failed,
the huge page will be added to hugepage_freelists. In this case, the
head page will hold the hwpoison flag, but the real poisoned tail page
hwpoison flag is not set, this will cause unpoison_memory() fail to
unpoison the previously poisoned page.

So add a check on hugetlb head page, and also need to ensure the
previously poisoned tail page in huge page raw_hwp_list.

Signed-off-by: luofei <[email protected]>
---
mm/memory-failure.c | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 14439806b5ef..fc571b0ceb9d 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2293,6 +2293,28 @@ core_initcall(memory_failure_init);
pr_info(fmt, pfn); \
})

+static bool hugetlb_page_head_poison(struct page *hpage, struct page *page)
+{
+ struct llist_head *head;
+ struct llist_node *t, *tnode;
+ struct raw_hwp_page *p;
+
+ if (PageHuge(page) && PageHWPoison(hpage) && HPageFreed(hpage))
+ return false;
+
+ if (HPageRawHwpUnreliable(hpage))
+ return false;
+
+ head = raw_hwp_list_head(hpage);
+ llist_for_each_safe(tnode, t, head->first) {
+ p = container_of(tnode, struct raw_hwp_page, node);
+ if (p->page == page)
+ return true;
+ }
+
+ return false;
+}
+
/**
* unpoison_memory - Unpoison a previously poisoned page
* @pfn: Page number of the to be unpoisoned page
@@ -2330,7 +2352,7 @@ int unpoison_memory(unsigned long pfn)
goto unlock_mutex;
}

- if (!PageHWPoison(p)) {
+ if (!PageHWPoison(p) && !hugetlb_page_head_poison(page, p)) {
unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n",
pfn, &unpoison_rs);
goto unlock_mutex;
--
2.27.0