The patch titled
Subject: mm: hugetlb: set the PageHWPoison to the raw error page
has been removed from the -mm tree. Its filename was
mm-hugetlb-set-the-pagehwpoison-to-the-raw-error-page.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
From: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Subject: mm: hugetlb: set the PageHWPoison to the raw error page
Because we reuse the first tail vmemmap page frame and remap it with
read-only, we cannot set the PageHWPosion on some tail pages. So we can
use the head[4].private (There are at least 128 struct page structures
associated with the optimized HugeTLB page, so using head[4].private is
safe) to record the real error page index and set the raw error page
PageHWPoison later.
We cannot have more poisoned tail pages. So a single slot is
sufficient. Why?
memory_failure()
if (PageHuge(page))
memory_failure_hugetlb()
head = compound_head(page)
if (TestSetPageHWPoison(head))
return
Because we do not clear the HWPoison of the head page, we cannot poison
another tail page.
Note: some pages might miss their poisoning (even without this patch).
Link: https://lkml.kernel.org/r/20210315092015.35396-7-songmuchun@xxxxxxxxxxxxx
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Tested-by: Chen Huang <chenhuang5@xxxxxxxxxx>
Tested-by: Bodeddula Balasubramaniam <bodeddub@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Balbir Singh <bsingharora@xxxxxxxxx>
Cc: Barry Song <song.bao.hua@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Joao Martins <joao.m.martins@xxxxxxxxxx>
Cc: Joerg Roedel <jroedel@xxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Mina Almasry <almasrymina@xxxxxxxxxx>
Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Cc: Oliver Neukum <oneukum@xxxxxxxx>
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Cc: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/hugetlb.h | 3 +
mm/hugetlb.c | 81 +++++++++++++++++++++++++++++++++-----
2 files changed, 75 insertions(+), 9 deletions(-)
--- a/include/linux/hugetlb.h~mm-hugetlb-set-the-pagehwpoison-to-the-raw-error-page
+++ a/include/linux/hugetlb.h
@@ -42,6 +42,9 @@ enum {
SUBPAGE_INDEX_CGROUP_RSVD, /* reuse page->private */
__MAX_CGROUP_SUBPAGE_INDEX = SUBPAGE_INDEX_CGROUP_RSVD,
#endif
+#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
+ SUBPAGE_INDEX_HWPOISON, /* reuse page->private */
+#endif
__NR_USED_SUBPAGE,
};
--- a/mm/hugetlb.c~mm-hugetlb-set-the-pagehwpoison-to-the-raw-error-page
+++ a/mm/hugetlb.c
@@ -1329,6 +1329,74 @@ static inline void destroy_compound_giga
unsigned int order) { }
#endif
+#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
+static inline void hwpoison_subpage_deliver(struct hstate *h, struct page *head)
+{
+ struct page *page;
+
+ if (!PageHWPoison(head) || !free_vmemmap_pages_per_hpage(h))
+ return;
+
+ page = head + page_private(head + SUBPAGE_INDEX_HWPOISON);
+
+ /*
+ * Move PageHWPoison flag from head page to the raw error page,
+ * which makes any subpages rather than the error page reusable.
+ */
+ if (page != head) {
+ SetPageHWPoison(page);
+ ClearPageHWPoison(head);
+ }
+}
+
+static inline void hwpoison_subpage_set(struct hstate *h, struct page *head,
+ struct page *page)
+{
+ if (!PageHWPoison(head))
+ return;
+
+ if (free_vmemmap_pages_per_hpage(h)) {
+ set_page_private(head + SUBPAGE_INDEX_HWPOISON, page - head);
+ } else if (page != head) {
+ /*
+ * Move PageHWPoison flag from head page to the raw error page,
+ * which makes any subpages rather than the error page reusable.
+ */
+ SetPageHWPoison(page);
+ ClearPageHWPoison(head);
+ }
+}
+
+static inline void hwpoison_subpage_clear(struct hstate *h, struct page *head)
+{
+ if (!PageHWPoison(head) || !free_vmemmap_pages_per_hpage(h))
+ return;
+
+ set_page_private(head + SUBPAGE_INDEX_HWPOISON, 0);
+}
+#else
+static inline void hwpoison_subpage_deliver(struct hstate *h, struct page *head)
+{
+}
+
+static inline void hwpoison_subpage_set(struct hstate *h, struct page *head,
+ struct page *page)
+{
+ if (PageHWPoison(head) && page != head) {
+ /*
+ * Move PageHWPoison flag from head page to the raw error page,
+ * which makes any subpages rather than the error page reusable.
+ */
+ SetPageHWPoison(page);
+ ClearPageHWPoison(head);
+ }
+}
+
+static inline void hwpoison_subpage_clear(struct hstate *h, struct page *head)
+{
+}
+#endif
+
static int update_and_free_page_surplus(struct hstate *h, struct page *page,
bool acct_surplus)
__releases(&hugetlb_lock) __acquires(&hugetlb_lock)
@@ -1833,22 +1901,17 @@ retry:
goto retry;
}
- /*
- * Move PageHWPoison flag from head page to the raw error page,
- * which makes any subpages rather than the error page reusable.
- */
- if (PageHWPoison(head) && page != head) {
- SetPageHWPoison(page);
- ClearPageHWPoison(head);
- }
+ hwpoison_subpage_set(h, head, page);
list_del(&head->lru);
ClearHPageFreed(page);
h->free_huge_pages--;
h->free_huge_pages_node[nid]--;
h->max_huge_pages--;
rc = update_and_free_page_surplus(h, head, false);
- if (rc)
+ if (rc) {
h->max_huge_pages++;
+ hwpoison_subpage_clear(h, head);
+ }
}
out:
spin_unlock(&hugetlb_lock);
_
Patches currently in -mm which might be from songmuchun@xxxxxxxxxxxxx are
mm-memcontrol-fix-kernel-stack-account.patch
mm-hugetlb-add-a-kernel-parameter-hugetlb_free_vmemmap.patch
mm-hugetlb-introduce-nr_free_vmemmap_pages-in-the-struct-hstate.patch
