mm-tracepoint: rename page-free events

Rename mm_page_free_direct into mm_page_free and mm_pagevec_free into
mm_page_free_batched

Since v2.6.33-5426-gc475dab the kernel triggers mm_page_free_direct for
all freed pages, not only for directly freed.  So, let's name it properly.
 For pages freed via page-list we also trigger mm_page_free_batched event.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/trace/events-kmem.txt b/Documentation/trace/events-kmem.txt
index aa82ee4..1948004 100644
--- a/Documentation/trace/events-kmem.txt
+++ b/Documentation/trace/events-kmem.txt
@@ -40,8 +40,8 @@
 ==================
 mm_page_alloc		  page=%p pfn=%lu order=%d migratetype=%d gfp_flags=%s
 mm_page_alloc_zone_locked page=%p pfn=%lu order=%u migratetype=%d cpu=%d percpu_refill=%d
-mm_page_free_direct	  page=%p pfn=%lu order=%d
-mm_pagevec_free		  page=%p pfn=%lu order=%d cold=%d
+mm_page_free		  page=%p pfn=%lu order=%d
+mm_page_free_batched	  page=%p pfn=%lu order=%d cold=%d
 
 These four events deal with page allocation and freeing. mm_page_alloc is
 a simple indicator of page allocator activity. Pages may be allocated from
@@ -53,13 +53,13 @@
 impairs performance by disabling interrupts, dirtying cache lines between
 CPUs and serialising many CPUs.
 
-When a page is freed directly by the caller, the mm_page_free_direct event
+When a page is freed directly by the caller, the only mm_page_free event
 is triggered. Significant amounts of activity here could indicate that the
 callers should be batching their activities.
 
-When pages are freed using a pagevec, the mm_pagevec_free is
-triggered. Broadly speaking, pages are taken off the LRU lock in bulk and
-freed in batch with a pagevec. Significant amounts of activity here could
+When pages are freed in batch, the also mm_page_free_batched is triggered.
+Broadly speaking, pages are taken off the LRU lock in bulk and
+freed in batch with a page list. Significant amounts of activity here could
 indicate that the system is under memory pressure and can also indicate
 contention on the zone->lru_lock.