From: Andi Kleen <ak@linux.intel.com>
Date: Fri, 22 Oct 2010 15:40:48 +0000 (+0200)
Subject: Merge branch 'hwpoison-hugepages' into hwpoison
X-Git-Tag: v2.6.37-rc1~109^2
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=46e387bbd82d438b9131e237e6e2cb55a825da49;p=linux-pvops.git

Merge branch 'hwpoison-hugepages' into hwpoison

Conflicts:
	mm/memory-failure.c
---

46e387bbd82d438b9131e237e6e2cb55a825da49
diff --cc mm/memory-failure.c
index 2044fe8920c2,14589a228e97..44a8cefeae6e
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@@ -1145,9 -1175,19 +1166,19 @@@ int unpoison_memory(unsigned long pfn
  	nr_pages = 1 << compound_order(page);
  
  	if (!get_page_unless_zero(page)) {
+ 		/*
+ 		 * Since HWPoisoned hugepage should have non-zero refcount,
+ 		 * race between memory failure and unpoison seems to happen.
+ 		 * In such case unpoison fails and memory failure runs
+ 		 * to the end.
+ 		 */
+ 		if (PageHuge(page)) {
+ 			pr_debug("MCE: Memory failure is now running on free hugepage %#lx\n", pfn);
+ 			return 0;
+ 		}
  		if (TestClearPageHWPoison(p))
  			atomic_long_sub(nr_pages, &mce_bad_pages);
 -		pr_debug("MCE: Software-unpoisoned free page %#lx\n", pfn);
 +		pr_info("MCE: Software-unpoisoned free page %#lx\n", pfn);
  		return 0;
  	}
  
@@@ -1159,12 -1199,12 +1190,12 @@@
  	 * the free buddy page pool.
  	 */
  	if (TestClearPageHWPoison(page)) {
 -		pr_debug("MCE: Software-unpoisoned page %#lx\n", pfn);
 +		pr_info("MCE: Software-unpoisoned page %#lx\n", pfn);
  		atomic_long_sub(nr_pages, &mce_bad_pages);
  		freeit = 1;
+ 		if (PageHuge(page))
+ 			clear_page_hwpoison_huge_page(page);
  	}
- 	if (PageHuge(p))
- 		clear_page_hwpoison_huge_page(page);
  	unlock_page(page);
  
  	put_page(page);
@@@ -1206,9 -1250,16 +1241,16 @@@ static int get_any_page(struct page *p
  	 * was free.
  	 */
  	set_migratetype_isolate(p);
+ 	/*
+ 	 * When the target page is a free hugepage, just remove it
+ 	 * from free hugepage list.
+ 	 */
  	if (!get_page_unless_zero(compound_head(p))) {
- 		if (is_free_buddy_page(p)) {
+ 		if (PageHuge(p)) {
 -			pr_debug("get_any_page: %#lx free huge page\n", pfn);
++			pr_info("get_any_page: %#lx free huge page\n", pfn);
+ 			ret = dequeue_hwpoisoned_huge_page(compound_head(p));
+ 		} else if (is_free_buddy_page(p)) {
 -			pr_debug("get_any_page: %#lx free buddy page\n", pfn);
 +			pr_info("get_any_page: %#lx free buddy page\n", pfn);
  			/* Set hwpoison bit while page is still isolated */
  			SetPageHWPoison(p);
  			ret = 0;