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* [PATCH] trace: don't call page_to_pfn() if page is NULL
@ 2012-09-20  6:04 Wen Congyang
  2012-09-20  6:28 ` Minchan Kim
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Wen Congyang @ 2012-09-20  6:04 UTC (permalink / raw)
  To: Steven Rostedt, Frederic Weisbecker, Ingo Molnar, Minchan Kim,
	Andrew Morton, khlebnikov, linux-kernel@vger.kernel.org

When allocating memory fails, page is NULL. page_to_pfn() will
cause the kernel panicked if we don't use sparsemem vmemmap.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>

---
 include/trace/events/kmem.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index 5f889f1..08fa272 100644
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -214,7 +214,7 @@ TRACE_EVENT(mm_page_alloc,
 
 	TP_printk("page=%p pfn=%lu order=%d migratetype=%d gfp_flags=%s",
 		__entry->page,
-		page_to_pfn(__entry->page),
+		__entry->page ? page_to_pfn(__entry->page) : 0,
 		__entry->order,
 		__entry->migratetype,
 		show_gfp_flags(__entry->gfp_flags))
@@ -240,7 +240,7 @@ DECLARE_EVENT_CLASS(mm_page,
 
 	TP_printk("page=%p pfn=%lu order=%u migratetype=%d percpu_refill=%d",
 		__entry->page,
-		page_to_pfn(__entry->page),
+		__entry->page ? page_to_pfn(__entry->page) : 0,
 		__entry->order,
 		__entry->migratetype,
 		__entry->order == 0)
-- 
1.7.1

^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2012-09-21 12:38 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-09-20  6:04 [PATCH] trace: don't call page_to_pfn() if page is NULL Wen Congyang
2012-09-20  6:28 ` Minchan Kim
2012-09-20 13:41   ` Steven Rostedt
2012-09-20 13:48 ` Steven Rostedt
2012-09-20 14:24   ` Mel Gorman
2012-09-21 12:37 ` [tip:perf/urgent] tracing: Don't " tip-bot for Wen Congyang

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