Merge branch 'linux-3.0.y' into cm.ics.new

Conflicts:
	mm/compaction.c

5 files changed, 36 insertions, 9 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 642e456..1175c24 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -330,17 +330,39 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
 		} else if (!locked)
 			spin_lock_irq(&zone->lru_lock);
 
+		/*
+		 * migrate_pfn does not necessarily start aligned to a
+		 * pageblock. Ensure that pfn_valid is called when moving
+		 * into a new MAX_ORDER_NR_PAGES range in case of large
+		 * memory holes within the zone
+		 */
+		if ((low_pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
+			if (!pfn_valid(low_pfn)) {
+				low_pfn += MAX_ORDER_NR_PAGES - 1;
+				continue;
+			}
+		}
+
 		if (!pfn_valid_within(low_pfn))
 			continue;
 		nr_scanned++;
 
-		/* Get the page and skip if free */
+		/*
+		 * Get the page and ensure the page is within the same zone.
+		 * See the comment in isolate_freepages about overlapping
+		 * nodes. It is deliberate that the new zone lock is not taken
+		 * as memory compaction should not move pages between nodes.
+		 */
 		page = pfn_to_page(low_pfn);
 
 		/* Watch for unexpected holes punched in the memmap */
 		if (!memmap_valid_within(low_pfn, page, zone))
 			continue;
 
+		if (page_zone(page) != zone)
+			continue;
+
+		/* Skip if free */
 		if (PageBuddy(page))
 			continue;
 
diff --git a/mm/filemap.c b/mm/filemap.c
index 3c981ba..b7d8603 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1379,15 +1379,12 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 	unsigned long seg = 0;
 	size_t count;
 	loff_t *ppos = &iocb->ki_pos;
-	struct blk_plug plug;
 
 	count = 0;
 	retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
 	if (retval)
 		return retval;
 
-	blk_start_plug(&plug);
-
 	/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
 	if (filp->f_flags & O_DIRECT) {
 		loff_t size;
@@ -1403,8 +1400,12 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 			retval = filemap_write_and_wait_range(mapping, pos,
 					pos + iov_length(iov, nr_segs) - 1);
 			if (!retval) {
+				struct blk_plug plug;
+
+				blk_start_plug(&plug);
 				retval = mapping->a_ops->direct_IO(READ, iocb,
 							iov, pos, nr_segs);
+				blk_finish_plug(&plug);
 			}
 			if (retval > 0) {
 				*ppos = pos + retval;
@@ -1460,7 +1461,6 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 			break;
 	}
 out:
-	blk_finish_plug(&plug);
 	return retval;
 }
 EXPORT_SYMBOL(generic_file_aio_read);
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index 93356cd..dee9429 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -263,7 +263,12 @@ found:
 							xip_pfn);
 		if (err == -ENOMEM)
 			return VM_FAULT_OOM;
-		BUG_ON(err);
+		/*
+		 * err == -EBUSY is fine, we've raced against another thread
+		 * that faulted-in the same page
+		 */
+		if (err != -EBUSY)
+			BUG_ON(err);
 		return VM_FAULT_NOPAGE;
 	} else {
 		int err, ret = VM_FAULT_OOM;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index cc5acf9..78a83e7 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2020,7 +2020,7 @@ static void collect_mm_slot(struct mm_slot *mm_slot)
 {
 	struct mm_struct *mm = mm_slot->mm;
 
-	VM_BUG_ON(!spin_is_locked(&khugepaged_mm_lock));
+	VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
 
 	if (khugepaged_test_exit(mm)) {
 		/* free mm_slot */
@@ -2048,7 +2048,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 	int progress = 0;
 
 	VM_BUG_ON(!pages);
-	VM_BUG_ON(!spin_is_locked(&khugepaged_mm_lock));
+	VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
 
 	if (khugepaged_scan.mm_slot)
 		mm_slot = khugepaged_scan.mm_slot;
diff --git a/mm/swap.c b/mm/swap.c
index 87627f1..4a1fc6d 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -667,7 +667,7 @@ void lru_add_page_tail(struct zone* zone,
 	VM_BUG_ON(!PageHead(page));
 	VM_BUG_ON(PageCompound(page_tail));
 	VM_BUG_ON(PageLRU(page_tail));
-	VM_BUG_ON(!spin_is_locked(&zone->lru_lock));
+	VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&zone->lru_lock));
 
 	SetPageLRU(page_tail);