- /*
- * ppage: poisoned page
- * if p is regular page(4k page)
- * ppage == real poisoned page;
- * else p is hugetlb or THP, ppage == head page.
- */
- ppage = hpage;
-
- if (PageTransHuge(hpage)) {
- /*
- * Verify that this isn't a hugetlbfs head page, the check for
- * PageAnon is just for avoid tripping a split_huge_page
- * internal debug check, as split_huge_page refuses to deal with
- * anything that isn't an anon page. PageAnon can't go away fro
- * under us because we hold a refcount on the hpage, without a
- * refcount on the hpage. split_huge_page can't be safely called
- * in the first place, having a refcount on the tail isn't
- * enough * to be safe.
- */
- if (!PageHuge(hpage) && PageAnon(hpage)) {
- if (unlikely(split_huge_page(hpage))) {
- /*
- * FIXME: if splitting THP is failed, it is
- * better to stop the following operation rather
- * than causing panic by unmapping. System might
- * survive if the page is freed later.
- */
- printk(KERN_INFO
- "MCE %#lx: failed to split THP\n", pfn);
-
- BUG_ON(!PageHWPoison(p));
- return SWAP_FAIL;
- }
- /*
- * We pinned the head page for hwpoison handling,
- * now we split the thp and we are interested in
- * the hwpoisoned raw page, so move the refcount
- * to it. Similarly, page lock is shifted.
- */
- if (hpage != p) {
- if (!(flags & MF_COUNT_INCREASED)) {
- put_page(hpage);
- get_page(p);
- }
- lock_page(p);
- unlock_page(hpage);
- *hpagep = p;
- }
- /* THP is split, so ppage should be the real poisoned page. */
- ppage = p;
- }
- }
-