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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

* Re: [PATCH] trace: don't call page_to_pfn() if page is NULL
  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
  2012-09-21 12:37 ` [tip:perf/urgent] tracing: Don't " tip-bot for Wen Congyang
  2 siblings, 1 reply; 6+ messages in thread
From: Minchan Kim @ 2012-09-20  6:28 UTC (permalink / raw)
  To: Wen Congyang
  Cc: Steven Rostedt, Frederic Weisbecker, Ingo Molnar, Andrew Morton,
	khlebnikov, linux-kernel@vger.kernel.org

On Thu, Sep 20, 2012 at 02:04:47PM +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 <wency@cn.fujitsu.com>

Nice catch.
I think it's a candidate of stable.

Reviewed-by: Minchan Kim <minchan@kernel.org>

-- 
Kind regards,
Minchan Kim

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

* Re: [PATCH] trace: don't call page_to_pfn() if page is NULL
  2012-09-20  6:28 ` Minchan Kim
@ 2012-09-20 13:41   ` Steven Rostedt
  0 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2012-09-20 13:41 UTC (permalink / raw)
  To: Minchan Kim
  Cc: Wen Congyang, Frederic Weisbecker, Ingo Molnar, Andrew Morton,
	khlebnikov, linux-kernel@vger.kernel.org, stable

On Thu, 2012-09-20 at 15:28 +0900, Minchan Kim wrote:
> On Thu, Sep 20, 2012 at 02:04:47PM +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 <wency@cn.fujitsu.com>
> 
> Nice catch.
> I think it's a candidate of stable.

Yeah, and it looks like it can go against all stable kernels as it was
introduced back in 2.6.32. I'll apply and start testing it.

Thanks,

-- Steve

> 
> Reviewed-by: Minchan Kim <minchan@kernel.org>
> 



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

* Re: [PATCH] trace: don't call page_to_pfn() if page is NULL
  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 13:48 ` 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
  2 siblings, 1 reply; 6+ messages in thread
From: Steven Rostedt @ 2012-09-20 13:48 UTC (permalink / raw)
  To: Wen Congyang, Mel Gorman
  Cc: Frederic Weisbecker, Ingo Molnar, Minchan Kim, Andrew Morton,
	khlebnikov, 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 <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)



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

* Re: [PATCH] trace: don't call page_to_pfn() if page is NULL
  2012-09-20 13:48 ` Steven Rostedt
@ 2012-09-20 14:24   ` Mel Gorman
  0 siblings, 0 replies; 6+ messages in thread
From: Mel Gorman @ 2012-09-20 14:24 UTC (permalink / raw)
  To: Steven Rostedt
  Cc: Wen Congyang, Frederic Weisbecker, Ingo Molnar, Minchan Kim,
	Andrew Morton, khlebnikov, linux-kernel@vger.kernel.org

On Thu, Sep 20, 2012 at 09:48:24AM -0400, Steven Rostedt wrote:
> Mel,
> 
> As you were the original author of this code, can I get your Acked-by?
> 

Sure. Problem as described is valid and the patch looks ok

Acked-by: Mel Gorman <mel@csn.ul.ie>

-- 
Mel Gorman
SUSE Labs

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

* [tip:perf/urgent] tracing: Don't call page_to_pfn() if page is NULL
  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 13:48 ` Steven Rostedt
@ 2012-09-21 12:37 ` tip-bot for Wen Congyang
  2 siblings, 0 replies; 6+ messages in thread
From: tip-bot for Wen Congyang @ 2012-09-21 12:37 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: mingo, linux-kernel, hpa, mingo, minchan, mel, stable, wency,
	fweisbec, rostedt, akpm, tglx

Commit-ID:  85f2a2ef1d0ab99523e0b947a2b723f5650ed6aa
Gitweb:     http://git.kernel.org/tip/85f2a2ef1d0ab99523e0b947a2b723f5650ed6aa
Author:     Wen Congyang <wency@cn.fujitsu.com>
AuthorDate: Thu, 20 Sep 2012 14:04:47 +0800
Committer:  Steven Rostedt <rostedt@goodmis.org>
CommitDate: Thu, 20 Sep 2012 15:51:16 -0400

tracing: Don't call page_to_pfn() if page is NULL

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

Link: http://lkml.kernel.org/r/505AB1FF.8020104@cn.fujitsu.com

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable <stable@vger.kernel.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 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)

^ 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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