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-rw-r--r--mm/memory-failure.c94
1 files changed, 72 insertions, 22 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 548fbd7..0207c2f 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -233,8 +233,8 @@ void shake_page(struct page *p, int access)
}
/*
- * Only all shrink_slab here (which would also
- * shrink other caches) if access is not potentially fatal.
+ * Only call shrink_slab here (which would also shrink other caches) if
+ * access is not potentially fatal.
*/
if (access) {
int nr;
@@ -386,8 +386,6 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill,
struct task_struct *tsk;
struct anon_vma *av;
- if (!PageHuge(page) && unlikely(split_huge_page(page)))
- return;
read_lock(&tasklist_lock);
av = page_lock_anon_vma(page);
if (av == NULL) /* Not actually mapped anymore */
@@ -856,6 +854,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
int ret;
int kill = 1;
struct page *hpage = compound_head(p);
+ struct page *ppage;
if (PageReserved(p) || PageSlab(p))
return SWAP_SUCCESS;
@@ -897,6 +896,44 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
}
/*
+ * 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;
+ }
+ /* THP is split, so ppage should be the real poisoned page. */
+ ppage = p;
+ }
+ }
+
+ /*
* First collect all the processes that have the page
* mapped in dirty form. This has to be done before try_to_unmap,
* because ttu takes the rmap data structures down.
@@ -905,12 +942,18 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
* there's nothing that can be done.
*/
if (kill)
- collect_procs(hpage, &tokill);
+ collect_procs(ppage, &tokill);
+
+ if (hpage != ppage)
+ lock_page_nosync(ppage);
- ret = try_to_unmap(hpage, ttu);
+ ret = try_to_unmap(ppage, ttu);
if (ret != SWAP_SUCCESS)
printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
- pfn, page_mapcount(hpage));
+ pfn, page_mapcount(ppage));
+
+ if (hpage != ppage)
+ unlock_page(ppage);
/*
* Now that the dirty bit has been propagated to the
@@ -921,7 +964,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
* use a more force-full uncatchable kill to prevent
* any accesses to the poisoned memory.
*/
- kill_procs_ao(&tokill, !!PageDirty(hpage), trapno,
+ kill_procs_ao(&tokill, !!PageDirty(ppage), trapno,
ret != SWAP_SUCCESS, p, pfn);
return ret;
@@ -1022,19 +1065,22 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
* The check (unnecessarily) ignores LRU pages being isolated and
* walked by the page reclaim code, however that's not a big loss.
*/
- if (!PageLRU(p) && !PageHuge(p))
- shake_page(p, 0);
- if (!PageLRU(p) && !PageHuge(p)) {
- /*
- * shake_page could have turned it free.
- */
- if (is_free_buddy_page(p)) {
- action_result(pfn, "free buddy, 2nd try", DELAYED);
- return 0;
+ if (!PageHuge(p) && !PageTransCompound(p)) {
+ if (!PageLRU(p))
+ shake_page(p, 0);
+ if (!PageLRU(p)) {
+ /*
+ * shake_page could have turned it free.
+ */
+ if (is_free_buddy_page(p)) {
+ action_result(pfn, "free buddy, 2nd try",
+ DELAYED);
+ return 0;
+ }
+ action_result(pfn, "non LRU", IGNORED);
+ put_page(p);
+ return -EBUSY;
}
- action_result(pfn, "non LRU", IGNORED);
- put_page(p);
- return -EBUSY;
}
/*
@@ -1064,7 +1110,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
* For error on the tail page, we should set PG_hwpoison
* on the head page to show that the hugepage is hwpoisoned
*/
- if (PageTail(p) && TestSetPageHWPoison(hpage)) {
+ if (PageHuge(p) && PageTail(p) && TestSetPageHWPoison(hpage)) {
action_result(pfn, "hugepage already hardware poisoned",
IGNORED);
unlock_page(hpage);
@@ -1295,7 +1341,10 @@ static int soft_offline_huge_page(struct page *page, int flags)
ret = migrate_huge_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0,
true);
if (ret) {
- putback_lru_pages(&pagelist);
+ struct page *page1, *page2;
+ list_for_each_entry_safe(page1, page2, &pagelist, lru)
+ put_page(page1);
+
pr_debug("soft offline: %#lx: migration failed %d, type %lx\n",
pfn, ret, page->flags);
if (ret > 0)
@@ -1419,6 +1468,7 @@ int soft_offline_page(struct page *page, int flags)
ret = migrate_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL,
0, true);
if (ret) {
+ putback_lru_pages(&pagelist);
pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
pfn, ret, page->flags);
if (ret > 0)