From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752362Ab2ITNs2 (ORCPT ); Thu, 20 Sep 2012 09:48:28 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:29777 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751655Ab2ITNs0 (ORCPT ); Thu, 20 Sep 2012 09:48:26 -0400 X-Authority-Analysis: v=2.0 cv=Vb91zSV9 c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=WnYo-2BfFuEA:10 a=5SG0PmZfjMsA:10 a=Q9fys5e9bTEA:10 a=meVymXHHAAAA:8 a=-t9bLuw0o0EA:10 a=omOdbC7AAAAA:8 a=t5L4QVpALLbyYhDqEvYA:9 a=PUjeQqilurYA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.115.198 Message-ID: <1348148904.13080.63.camel@gandalf.local.home> Subject: Re: [PATCH] trace: don't call page_to_pfn() if page is NULL From: Steven Rostedt To: Wen Congyang , Mel Gorman Cc: Frederic Weisbecker , Ingo Molnar , Minchan Kim , Andrew Morton , khlebnikov@openvz.org, "linux-kernel@vger.kernel.org" Date: Thu, 20 Sep 2012 09:48:24 -0400 In-Reply-To: <505AB1FF.8020104@cn.fujitsu.com> References: <505AB1FF.8020104@cn.fujitsu.com> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.4.3-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Mel, As you were the original author of this code, can I get your Acked-by? Thanks, -- Steve On Thu, 2012-09-20 at 14:04 +0800, Wen Congyang wrote: > 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 > > --- > 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)