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-rw-r--r--mm/hugetlb.c41
-rw-r--r--mm/memory-failure.c14
2 files changed, 50 insertions, 5 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 995c8d6..0540783 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -924,6 +924,31 @@ struct hstate *size_to_hstate(unsigned long size)
return NULL;
}
+/*
+ * Test to determine whether the hugepage is "active/in-use" (i.e. being linked
+ * to hstate->hugepage_activelist.)
+ *
+ * This function can be called for tail pages, but never returns true for them.
+ */
+bool page_huge_active(struct page *page)
+{
+ VM_BUG_ON_PAGE(!PageHuge(page), page);
+ return PageHead(page) && PagePrivate(&page[1]);
+}
+
+/* never called for tail page */
+static void set_page_huge_active(struct page *page)
+{
+ VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
+ SetPagePrivate(&page[1]);
+}
+
+static void clear_page_huge_active(struct page *page)
+{
+ VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
+ ClearPagePrivate(&page[1]);
+}
+
void free_huge_page(struct page *page)
{
/*
@@ -952,6 +977,7 @@ void free_huge_page(struct page *page)
restore_reserve = true;
spin_lock(&hugetlb_lock);
+ clear_page_huge_active(page);
hugetlb_cgroup_uncharge_page(hstate_index(h),
pages_per_huge_page(h), page);
if (restore_reserve)
@@ -2972,6 +2998,7 @@ retry_avoidcopy:
copy_user_huge_page(new_page, old_page, address, vma,
pages_per_huge_page(h));
__SetPageUptodate(new_page);
+ set_page_huge_active(new_page);
mmun_start = address & huge_page_mask(h);
mmun_end = mmun_start + huge_page_size(h);
@@ -3084,6 +3111,7 @@ retry:
}
clear_huge_page(page, address, pages_per_huge_page(h));
__SetPageUptodate(page);
+ set_page_huge_active(page);
if (vma->vm_flags & VM_MAYSHARE) {
int err;
@@ -3913,19 +3941,26 @@ int dequeue_hwpoisoned_huge_page(struct page *hpage)
bool isolate_huge_page(struct page *page, struct list_head *list)
{
+ bool ret = true;
+
VM_BUG_ON_PAGE(!PageHead(page), page);
- if (!get_page_unless_zero(page))
- return false;
spin_lock(&hugetlb_lock);
+ if (!page_huge_active(page) || !get_page_unless_zero(page)) {
+ ret = false;
+ goto unlock;
+ }
+ clear_page_huge_active(page);
list_move_tail(&page->lru, list);
+unlock:
spin_unlock(&hugetlb_lock);
- return true;
+ return ret;
}
void putback_active_hugepage(struct page *page)
{
VM_BUG_ON_PAGE(!PageHead(page), page);
spin_lock(&hugetlb_lock);
+ set_page_huge_active(page);
list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist);
spin_unlock(&hugetlb_lock);
put_page(page);
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 5fd8931..d9359b7 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1586,8 +1586,18 @@ static int soft_offline_huge_page(struct page *page, int flags)
}
unlock_page(hpage);
- /* Keep page count to indicate a given hugepage is isolated. */
- list_move(&hpage->lru, &pagelist);
+ ret = isolate_huge_page(hpage, &pagelist);
+ if (ret) {
+ /*
+ * get_any_page() and isolate_huge_page() takes a refcount each,
+ * so need to drop one here.
+ */
+ put_page(hpage);
+ } else {
+ pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
+ return -EBUSY;
+ }
+
ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
MIGRATE_SYNC, MR_MEMORY_FAILURE);
if (ret) {
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