On 2024/8/21 15:40, Miaohe Lin wrote:
On 2024/8/17 16:49, Kefeng Wang wrote:
Add unmap_posioned_folio() helper which will be reused by
do_migrate_range() from memory hotplug soon.
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
mm/internal.h | 9 +++++++++
mm/memory-failure.c | 43 ++++++++++++++++++++++++++-----------------
2 files changed, 35 insertions(+), 17 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h
index d7aac802efa5..74490b8ac63d 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1045,6 +1045,8 @@ static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
/*
* mm/memory-failure.c
*/
+#ifdef CONFIG_MEMORY_FAILURE
+int unmap_posioned_folio(struct folio *folio, enum ttu_flags ttu);
void shake_folio(struct folio *folio);
extern int hwpoison_filter(struct page *p);
@@ -1065,6 +1067,13 @@ void add_to_kill_ksm(struct task_struct *tsk, struct page *p,
unsigned long ksm_addr);
unsigned long page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
+#else
+static inline int unmap_posioned_folio(struct folio *folio, enum ttu_flags ttu)
+{
+ return 0;
+}
+#endif
+
extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long,
unsigned long, unsigned long,
unsigned long, unsigned long);
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 353254537b54..93848330de1f 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1554,6 +1554,30 @@ static int get_hwpoison_page(struct page *p, unsigned long flags)
return ret;
}
+int unmap_posioned_folio(struct folio *folio, enum ttu_flags ttu)
Should it be unmap_poisoned_folio ? i.e. s/posioned/poisoned/ :)
Oh, my bad.
+{
+ if (folio_test_hugetlb(folio) && !folio_test_anon(folio)) {
+ struct address_space *mapping;
+ /*
+ * For hugetlb pages in shared mappings, try_to_unmap
+ * could potentially call huge_pmd_unshare. Because of
+ * this, take semaphore in write mode here and set
+ * TTU_RMAP_LOCKED to indicate we have taken the lock
+ * at this higher level.
+ */
+ mapping = hugetlb_folio_mapping_lock_write(folio);
+ if (!mapping)
+ return -EAGAIN;
+
+ try_to_unmap(folio, ttu|TTU_RMAP_LOCKED);
+ i_mmap_unlock_write(mapping);
+ } else {
+ try_to_unmap(folio, ttu);
+ }
+
+ return 0;
It seems return value is not really needed? We will check folio_mapped below.
It is just to keep the same as before, but
+}
+
/*
* Do all that is necessary to remove user space mappings. Unmap
* the pages and send SIGBUS to the processes if the data was dirty.
@@ -1615,23 +1639,8 @@ static bool hwpoison_user_mappings(struct folio *folio, struct page *p,
*/
collect_procs(folio, p, &tokill, flags & MF_ACTION_REQUIRED);
- if (folio_test_hugetlb(folio) && !folio_test_anon(folio)) {
- /*
- * For hugetlb pages in shared mappings, try_to_unmap
- * could potentially call huge_pmd_unshare. Because of
- * this, take semaphore in write mode here and set
- * TTU_RMAP_LOCKED to indicate we have taken the lock
- * at this higher level.
- */
- mapping = hugetlb_folio_mapping_lock_write(folio);
- if (mapping) {
- try_to_unmap(folio, ttu|TTU_RMAP_LOCKED);
- i_mmap_unlock_write(mapping);
- } else
- pr_info("%#lx: could not lock mapping for mapped huge page\n", pfn);
- } else {
- try_to_unmap(folio, ttu);
- }
+ if (unmap_posioned_folio(folio, ttu))
+ pr_info("%#lx: could not lock mapping for mapped huge page\n", pfn);
It might be better to pr_info inside the unmap_posioned_folio? unmap_posioned_folio might fail due
to other reasons in the future anyway.
think it again, we have another check and print when recheck
folio_mapped(), so killing the return value and this print for hugepage
is better, and in memory-hotplug, we don't pr_warn for this case.
I will remove return and this print if no objection.
Thanks.
.
