[PATCH v1 08/11] mm: hwpoison: soft offline supports thp migration

[Naoya Horiguchi]

This patch enables thp migration for soft offline.

Signed-off-by: Naoya Horiguchi <n-horigu...@ah.jp.nec.com>
---
 mm/memory-failure.c | 31 ++++++++++++-------------------
 1 file changed, 12 insertions(+), 19 deletions(-)

diff --git v4.5-rc5-mmotm-2016-02-24-16-18/mm/memory-failure.c 
v4.5-rc5-mmotm-2016-02-24-16-18_patched/mm/memory-failure.c
index bfb63c6..9099e78 100644
--- v4.5-rc5-mmotm-2016-02-24-16-18/mm/memory-failure.c
+++ v4.5-rc5-mmotm-2016-02-24-16-18_patched/mm/memory-failure.c
@@ -1490,7 +1490,17 @@ static struct page *new_page(struct page *p, unsigned 
long private, int **x)
        if (PageHuge(p))
                return alloc_huge_page_node(page_hstate(compound_head(p)),
                                                   nid);
-       else
+       else if (thp_migration_supported() && PageTransHuge(p)) {
+               struct page *thp;
+
+               thp = alloc_pages_node(nid,
+                       (GFP_TRANSHUGE | __GFP_THISNODE) & ~__GFP_RECLAIM,
+                       HPAGE_PMD_ORDER);
+               if (!thp)
+                       return NULL;
+               prep_transhuge_page(thp);
+               return thp;
+       } else
                return __alloc_pages_node(nid, GFP_HIGHUSER_MOVABLE, 0);
 }
 
@@ -1693,28 +1703,11 @@ static int __soft_offline_page(struct page *page, int 
flags)
 static int soft_offline_in_use_page(struct page *page, int flags)
 {
        int ret;
-       struct page *hpage = compound_head(page);
-
-       if (!PageHuge(page) && PageTransHuge(hpage)) {
-               lock_page(hpage);
-               if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
-                       unlock_page(hpage);
-                       if (!PageAnon(hpage))
-                               pr_info("soft offline: %#lx: non anonymous 
thp\n", page_to_pfn(page));
-                       else
-                               pr_info("soft offline: %#lx: thp split 
failed\n", page_to_pfn(page));
-                       put_hwpoison_page(hpage);
-                       return -EBUSY;
-               }
-               unlock_page(hpage);
-               get_hwpoison_page(page);
-               put_hwpoison_page(hpage);
-       }
 
        if (PageHuge(page))
                ret = soft_offline_huge_page(page, flags);
        else
-               ret = __soft_offline_page(page, flags);
+               ret = __soft_offline_page(compound_head(page), flags);
 
        return ret;
 }
-- 
2.7.0