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From: Wen Congyang <wency@cn.fujitsu.com>
To: Steven Rostedt <rostedt@goodmis.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Ingo Molnar <mingo@redhat.com>, Minchan Kim <minchan@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	khlebnikov@openvz.org,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: [PATCH] trace: don't call page_to_pfn() if page is NULL
Date: Thu, 20 Sep 2012 14:04:47 +0800	[thread overview]
Message-ID: <505AB1FF.8020104@cn.fujitsu.com> (raw)

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

             reply	other threads:[~2012-09-20  5:59 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-20  6:04 Wen Congyang [this message]
2012-09-20  6:28 ` [PATCH] trace: don't call page_to_pfn() if page is NULL 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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