When a newly poisoned subpage ends up in an already poisoned hugetlb folio, 'num_poisoned_pages' is incremented, but the per node ->mf_stats is not. Fix the inconsistency by designating action_result() to update them both.
While at it, define __get_huge_page_for_hwpoison() return values in terms of symbol names for better readibility. Also rename folio_set_hugetlb_hwpoison() to hugetlb_update_hwpoison() since the function does more than the conventional bit setting and the fact three possible return values are expected.
Fixes: 18f41fa616ee4 ("mm: memory-failure: bump memory failure stats to pglist_data") Cc: stable@vger.kernel.org Signed-off-by: Jane Chu jane.chu@oracle.com --- v2 -> v3: No change. v1 -> v2: adapted David and Liam's comment, define __get_huge_page_for_hwpoison() return values in terms of symbol names instead of naked integers for better readibility. #define instead of enum is used since the function has footprint outside MF, just try to limit the MF specifics local. also renamed folio_set_hugetlb_hwpoison() to hugetlb_update_hwpoison() since the function does more than the conventional bit setting and the fact three possible return values are expected.
--- mm/memory-failure.c | 56 ++++++++++++++++++++++++++------------------- 1 file changed, 33 insertions(+), 23 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index fbc5a01260c8..8b47e8a1b12d 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1883,12 +1883,18 @@ static unsigned long __folio_free_raw_hwp(struct folio *folio, bool move_flag) return count; }
-static int folio_set_hugetlb_hwpoison(struct folio *folio, struct page *page) +#define MF_HUGETLB_ALREADY_POISONED 3 /* already poisoned */ +#define MF_HUGETLB_ACC_EXISTING_POISON 4 /* accessed existing poisoned page */ +/* + * Set hugetlb folio as hwpoisoned, update folio private raw hwpoison list + * to keep track of the poisoned pages. + */ +static int hugetlb_update_hwpoison(struct folio *folio, struct page *page) { struct llist_head *head; struct raw_hwp_page *raw_hwp; struct raw_hwp_page *p; - int ret = folio_test_set_hwpoison(folio) ? -EHWPOISON : 0; + int ret = folio_test_set_hwpoison(folio) ? MF_HUGETLB_ALREADY_POISONED : 0;
/* * Once the hwpoison hugepage has lost reliable raw error info, @@ -1896,20 +1902,18 @@ static int folio_set_hugetlb_hwpoison(struct folio *folio, struct page *page) * so skip to add additional raw error info. */ if (folio_test_hugetlb_raw_hwp_unreliable(folio)) - return -EHWPOISON; + return MF_HUGETLB_ALREADY_POISONED; + head = raw_hwp_list_head(folio); llist_for_each_entry(p, head->first, node) { if (p->page == page) - return -EHWPOISON; + return MF_HUGETLB_ACC_EXISTING_POISON; }
raw_hwp = kmalloc(sizeof(struct raw_hwp_page), GFP_ATOMIC); if (raw_hwp) { raw_hwp->page = page; llist_add(&raw_hwp->node, head); - /* the first error event will be counted in action_result(). */ - if (ret) - num_poisoned_pages_inc(page_to_pfn(page)); } else { /* * Failed to save raw error info. We no longer trace all @@ -1955,32 +1959,30 @@ void folio_clear_hugetlb_hwpoison(struct folio *folio) folio_free_raw_hwp(folio, true); }
+#define MF_HUGETLB_FREED 0 /* freed hugepage */ +#define MF_HUGETLB_IN_USED 1 /* in-use hugepage */ +#define MF_NOT_HUGETLB 2 /* not a hugepage */ + /* * Called from hugetlb code with hugetlb_lock held. - * - * Return values: - * 0 - free hugepage - * 1 - in-use hugepage - * 2 - not a hugepage - * -EBUSY - the hugepage is busy (try to retry) - * -EHWPOISON - the hugepage is already hwpoisoned */ int __get_huge_page_for_hwpoison(unsigned long pfn, int flags, bool *migratable_cleared) { struct page *page = pfn_to_page(pfn); struct folio *folio = page_folio(page); - int ret = 2; /* fallback to normal page handling */ + int ret = MF_NOT_HUGETLB; bool count_increased = false; + int rc;
if (!folio_test_hugetlb(folio)) goto out;
if (flags & MF_COUNT_INCREASED) { - ret = 1; + ret = MF_HUGETLB_IN_USED; count_increased = true; } else if (folio_test_hugetlb_freed(folio)) { - ret = 0; + ret = MF_HUGETLB_FREED; } else if (folio_test_hugetlb_migratable(folio)) { ret = folio_try_get(folio); if (ret) @@ -1991,8 +1993,9 @@ int __get_huge_page_for_hwpoison(unsigned long pfn, int flags, goto out; }
- if (folio_set_hugetlb_hwpoison(folio, page)) { - ret = -EHWPOISON; + rc = hugetlb_update_hwpoison(folio, page); + if (rc >= MF_HUGETLB_ALREADY_POISONED) { + ret = rc; goto out; }
@@ -2029,22 +2032,29 @@ static int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *hugetlb *hugetlb = 1; retry: res = get_huge_page_for_hwpoison(pfn, flags, &migratable_cleared); - if (res == 2) { /* fallback to normal page handling */ + switch (res) { + case MF_NOT_HUGETLB: /* fallback to normal page handling */ *hugetlb = 0; return 0; - } else if (res == -EHWPOISON) { + case MF_HUGETLB_ALREADY_POISONED: + case MF_HUGETLB_ACC_EXISTING_POISON: if (flags & MF_ACTION_REQUIRED) { folio = page_folio(p); res = kill_accessing_process(current, folio_pfn(folio), flags); } - action_result(pfn, MF_MSG_ALREADY_POISONED, MF_FAILED); + if (res == MF_HUGETLB_ALREADY_POISONED) + action_result(pfn, MF_MSG_ALREADY_POISONED, MF_FAILED); + else + action_result(pfn, MF_MSG_HUGE, MF_FAILED); return res; - } else if (res == -EBUSY) { + case -EBUSY: if (!(flags & MF_NO_RETRY)) { flags |= MF_NO_RETRY; goto retry; } return action_result(pfn, MF_MSG_GET_HWPOISON, MF_IGNORED); + default: + break; }
folio = page_folio(p);
On 12/23/2025 12:50 AM, David Hildenbrand (Red Hat) wrote:
On 12/23/25 02:21, Jane Chu wrote:
When a newly poisoned subpage ends up in an already poisoned hugetlb folio, 'num_poisoned_pages' is incremented, but the per node ->mf_stats is not. Fix the inconsistency by designating action_result() to update them both.
While at it, define __get_huge_page_for_hwpoison() return values in terms of symbol names for better readibility. Also rename folio_set_hugetlb_hwpoison() to hugetlb_update_hwpoison() since the function does more than the conventional bit setting and the fact three possible return values are expected.
Fixes: 18f41fa616ee4 ("mm: memory-failure: bump memory failure stats to pglist_data") Cc: stable@vger.kernel.org Signed-off-by: Jane Chu jane.chu@oracle.com
v2 -> v3: No change. v1 -> v2: adapted David and Liam's comment, define __get_huge_page_for_hwpoison() return values in terms of symbol names instead of naked integers for better readibility. #define instead of enum is used since the function has footprint outside MF, just try to limit the MF specifics local. also renamed folio_set_hugetlb_hwpoison() to hugetlb_update_hwpoison() since the function does more than the conventional bit setting and the fact three possible return values are expected.
mm/memory-failure.c | 56 ++++++++++++++++++++++++++------------------- 1 file changed, 33 insertions(+), 23 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index fbc5a01260c8..8b47e8a1b12d 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1883,12 +1883,18 @@ static unsigned long __folio_free_raw_hwp(struct folio *folio, bool move_flag) return count; } -static int folio_set_hugetlb_hwpoison(struct folio *folio, struct page *page) +#define MF_HUGETLB_ALREADY_POISONED 3 /* already poisoned */ +#define MF_HUGETLB_ACC_EXISTING_POISON 4 /* accessed existing poisoned page */
What happened to the idea of using an enum?
I briefly mentioned the reason of using #define instead of enum in the v1 -> v2 comment, more below.
+/*
- Set hugetlb folio as hwpoisoned, update folio private raw hwpoison
list
- to keep track of the poisoned pages.
- */
+static int hugetlb_update_hwpoison(struct folio *folio, struct page *page) { struct llist_head *head; struct raw_hwp_page *raw_hwp; struct raw_hwp_page *p; - int ret = folio_test_set_hwpoison(folio) ? -EHWPOISON : 0; + int ret = folio_test_set_hwpoison(folio) ? MF_HUGETLB_ALREADY_POISONED : 0; /* * Once the hwpoison hugepage has lost reliable raw error info, @@ -1896,20 +1902,18 @@ static int folio_set_hugetlb_hwpoison(struct folio *folio, struct page *page) * so skip to add additional raw error info. */ if (folio_test_hugetlb_raw_hwp_unreliable(folio)) - return -EHWPOISON; + return MF_HUGETLB_ALREADY_POISONED;
head = raw_hwp_list_head(folio); llist_for_each_entry(p, head->first, node) { if (p->page == page) - return -EHWPOISON; + return MF_HUGETLB_ACC_EXISTING_POISON; } raw_hwp = kmalloc(sizeof(struct raw_hwp_page), GFP_ATOMIC); if (raw_hwp) { raw_hwp->page = page; llist_add(&raw_hwp->node, head); - /* the first error event will be counted in action_result(). */ - if (ret) - num_poisoned_pages_inc(page_to_pfn(page)); } else { /* * Failed to save raw error info. We no longer trace all @@ -1955,32 +1959,30 @@ void folio_clear_hugetlb_hwpoison(struct folio *folio) folio_free_raw_hwp(folio, true); } +#define MF_HUGETLB_FREED 0 /* freed hugepage */ +#define MF_HUGETLB_IN_USED 1 /* in-use hugepage */ +#define MF_NOT_HUGETLB 2 /* not a hugepage */
If you're already dealing with negative error codes, "MF_NOT_HUGETLB" nicely translated to -EINVAL.
Agreed, thanks, will make the change in next round.
But I wonder if it would be cleaner to just define all values in an enum and return that enum instead of an int from the functions.
enum md_hugetlb_status { MF_HUGETLB_INVALID, /* not a hugetlb folio */ MF_HUGETLB_BUSY, /* busy, retry later */ MF_HUGETLB_FREED, /* hugetlb folio was freed */ MF_HUGETLB_IN_USED, /* ??? no idea what that really means */ MF_HUGETLB_FOLIO_PRE_POISONED, /* folio already poisoned, per- page information unclear */ MF_HUGETLB_PAGE_PRE_POISONED, /* exact page already poisoned */ }
enum is nicer than #define for sure, the only concern I have is that, this enum as a return type from _get_huge_page_for_hwpoison()/ get_huge_page_for_hwpoison() will leave footprint in include/linux/mm.h that declares _get_huge_page_for_hwpoison(), include/linux/hugetlb.h that declares/defines get_huge_page_for_hwpoison(), and mm/hugetlb.c.
Is there a neat way? or, am I nitpicking? :)
thanks, -jane
On 12/23/25 02:21, Jane Chu wrote:
When a newly poisoned subpage ends up in an already poisoned hugetlb folio, 'num_poisoned_pages' is incremented, but the per node ->mf_stats is not. Fix the inconsistency by designating action_result() to update them both.
While at it, define __get_huge_page_for_hwpoison() return values in terms of symbol names for better readibility. Also rename folio_set_hugetlb_hwpoison() to hugetlb_update_hwpoison() since the function does more than the conventional bit setting and the fact three possible return values are expected.
Fixes: 18f41fa616ee4 ("mm: memory-failure: bump memory failure stats to pglist_data") Cc: stable@vger.kernel.org Signed-off-by: Jane Chu jane.chu@oracle.com
v2 -> v3: No change. v1 -> v2: adapted David and Liam's comment, define __get_huge_page_for_hwpoison() return values in terms of symbol names instead of naked integers for better readibility. #define instead of enum is used since the function has footprint outside MF, just try to limit the MF specifics local. also renamed folio_set_hugetlb_hwpoison() to hugetlb_update_hwpoison() since the function does more than the conventional bit setting and the fact three possible return values are expected.
mm/memory-failure.c | 56 ++++++++++++++++++++++++++------------------- 1 file changed, 33 insertions(+), 23 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index fbc5a01260c8..8b47e8a1b12d 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1883,12 +1883,18 @@ static unsigned long __folio_free_raw_hwp(struct folio *folio, bool move_flag) return count; } -static int folio_set_hugetlb_hwpoison(struct folio *folio, struct page *page) +#define MF_HUGETLB_ALREADY_POISONED 3 /* already poisoned */ +#define MF_HUGETLB_ACC_EXISTING_POISON 4 /* accessed existing poisoned page */
What happened to the idea of using an enum?
+/*
- Set hugetlb folio as hwpoisoned, update folio private raw hwpoison list
- to keep track of the poisoned pages.
- */
+static int hugetlb_update_hwpoison(struct folio *folio, struct page *page) { struct llist_head *head; struct raw_hwp_page *raw_hwp; struct raw_hwp_page *p;
- int ret = folio_test_set_hwpoison(folio) ? -EHWPOISON : 0;
- int ret = folio_test_set_hwpoison(folio) ? MF_HUGETLB_ALREADY_POISONED : 0;
/* * Once the hwpoison hugepage has lost reliable raw error info, @@ -1896,20 +1902,18 @@ static int folio_set_hugetlb_hwpoison(struct folio *folio, struct page *page) * so skip to add additional raw error info. */ if (folio_test_hugetlb_raw_hwp_unreliable(folio))
return -EHWPOISON;
return MF_HUGETLB_ALREADY_POISONED;- head = raw_hwp_list_head(folio); llist_for_each_entry(p, head->first, node) { if (p->page == page)
return -EHWPOISON;
return MF_HUGETLB_ACC_EXISTING_POISON;raw_hwp = kmalloc(sizeof(struct raw_hwp_page), GFP_ATOMIC); if (raw_hwp) { raw_hwp->page = page; llist_add(&raw_hwp->node, head);
/* the first error event will be counted in action_result(). */if (ret)num_poisoned_pages_inc(page_to_pfn(page));
- Failed to save raw error info. We no longer trace all
@@ -1955,32 +1959,30 @@ void folio_clear_hugetlb_hwpoison(struct folio *folio) folio_free_raw_hwp(folio, true); } +#define MF_HUGETLB_FREED 0 /* freed hugepage */ +#define MF_HUGETLB_IN_USED 1 /* in-use hugepage */ +#define MF_NOT_HUGETLB 2 /* not a hugepage */
If you're already dealing with negative error codes, "MF_NOT_HUGETLB" nicely translated to -EINVAL.
But I wonder if it would be cleaner to just define all values in an enum and return that enum instead of an int from the functions.
enum md_hugetlb_status { MF_HUGETLB_INVALID, /* not a hugetlb folio */ MF_HUGETLB_BUSY, /* busy, retry later */ MF_HUGETLB_FREED, /* hugetlb folio was freed */ MF_HUGETLB_IN_USED, /* ??? no idea what that really means */ MF_HUGETLB_FOLIO_PRE_POISONED, /* folio already poisoned, per-page information unclear */ MF_HUGETLB_PAGE_PRE_POISONED, /* exact page already poisoned */ }
linux-stable-mirror@lists.linaro.org
-
David Hildenbrand (Red Hat) -
Jane Chu -
jane.chu＠oracle.com