Re: [PATCH 5/10] memory-hotplug : memory-hotplug: check page type in get_page_bootmem

2012-10-18 Thread Yasuaki Ishimatsu 

Hi Kosaki,

Sorry for late reply.

2012/10/13 4:28, KOSAKI Motohiro wrote:

On Thu, Oct 4, 2012 at 10:32 PM, Yasuaki Ishimatsu
isimatu.yasu...@jp.fujitsu.com wrote:

The function get_page_bootmem() may be called more than one time to the same
page. There is no need to set page's type, private if the function is not
the first time called to the page.

Note: the patch is just optimization and does not fix any problem.

CC: David Rientjes rient...@google.com
CC: Jiang Liu liu...@gmail.com
CC: Len Brown len.br...@intel.com
CC: Christoph Lameter c...@linux.com
Cc: Minchan Kim minchan@gmail.com
CC: Andrew Morton a...@linux-foundation.org
CC: KOSAKI Motohiro kosaki.motoh...@jp.fujitsu.com
CC: Wen Congyang we...@cn.fujitsu.com
Signed-off-by: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
---
  mm/memory_hotplug.c |   15 +++
  1 file changed, 11 insertions(+), 4 deletions(-)

Index: linux-3.6/mm/memory_hotplug.c
===
--- linux-3.6.orig/mm/memory_hotplug.c  2012-10-04 18:29:58.284676075 +0900
+++ linux-3.6/mm/memory_hotplug.c   2012-10-04 18:30:03.454680542 +0900
@@ -95,10 +95,17 @@ static void release_memory_resource(stru
  static void get_page_bootmem(unsigned long info,  struct page *page,
  unsigned long type)
  {
-   page-lru.next = (struct list_head *) type;
-   SetPagePrivate(page);
-   set_page_private(page, info);
-   atomic_inc(page-_count);
+   unsigned long page_type;
+
+   page_type = (unsigned long)page-lru.next;


If I understand correctly, page-lru.next might be uninitialized yet.


Ah yes. I was misunderstanding...

Hi Wen,

When you update the physical hot remove patch-set, please drop the patch.

Thanks,
Yasuaki Ishimatsu  
 

Moreover, I have no seen any good effect in this patch. I don't understand
why we need to increase code complexity.




+   if (page_type  MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
+   page_type  MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE){
+   page-lru.next = (struct list_head *)type;
+   SetPagePrivate(page);
+   set_page_private(page, info);
+   atomic_inc(page-_count);
+   } else
+   atomic_inc(page-_count);
  }

  /* reference to __meminit __free_pages_bootmem is valid

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Re: [PATCH 5/10] memory-hotplug : memory-hotplug: check page type in get_page_bootmem

2012-10-18 Thread Wen Congyang 
At 10/19/2012 08:49 AM, Yasuaki Ishimatsu Wrote:
 Hi Kosaki,
 
 Sorry for late reply.
 
 2012/10/13 4:28, KOSAKI Motohiro wrote:
 On Thu, Oct 4, 2012 at 10:32 PM, Yasuaki Ishimatsu
 isimatu.yasu...@jp.fujitsu.com wrote:
 The function get_page_bootmem() may be called more than one time to
 the same
 page. There is no need to set page's type, private if the function is
 not
 the first time called to the page.

 Note: the patch is just optimization and does not fix any problem.

 CC: David Rientjes rient...@google.com
 CC: Jiang Liu liu...@gmail.com
 CC: Len Brown len.br...@intel.com
 CC: Christoph Lameter c...@linux.com
 Cc: Minchan Kim minchan@gmail.com
 CC: Andrew Morton a...@linux-foundation.org
 CC: KOSAKI Motohiro kosaki.motoh...@jp.fujitsu.com
 CC: Wen Congyang we...@cn.fujitsu.com
 Signed-off-by: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
 ---
   mm/memory_hotplug.c |   15 +++
   1 file changed, 11 insertions(+), 4 deletions(-)

 Index: linux-3.6/mm/memory_hotplug.c
 ===
 --- linux-3.6.orig/mm/memory_hotplug.c  2012-10-04 18:29:58.284676075
 +0900
 +++ linux-3.6/mm/memory_hotplug.c   2012-10-04 18:30:03.454680542
 +0900
 @@ -95,10 +95,17 @@ static void release_memory_resource(stru
   static void get_page_bootmem(unsigned long info,  struct page *page,
   unsigned long type)
   {
 -   page-lru.next = (struct list_head *) type;
 -   SetPagePrivate(page);
 -   set_page_private(page, info);
 -   atomic_inc(page-_count);
 +   unsigned long page_type;
 +
 +   page_type = (unsigned long)page-lru.next;

 If I understand correctly, page-lru.next might be uninitialized yet.
 
 Ah yes. I was misunderstanding...
 
 Hi Wen,
 
 When you update the physical hot remove patch-set, please drop the patch.

OK

Thanks
Wen Congyang

 
 Thanks,
 Yasuaki Ishimatsu   
 Moreover, I have no seen any good effect in this patch. I don't
 understand
 why we need to increase code complexity.



 +   if (page_type  MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
 +   page_type  MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE){
 +   page-lru.next = (struct list_head *)type;
 +   SetPagePrivate(page);
 +   set_page_private(page, info);
 +   atomic_inc(page-_count);
 +   } else
 +   atomic_inc(page-_count);
   }

   /* reference to __meminit __free_pages_bootmem is valid

 -- 
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Re: [PATCH 5/10] memory-hotplug : memory-hotplug: check page type in get_page_bootmem

2012-10-12 Thread KOSAKI Motohiro 
On Thu, Oct 4, 2012 at 10:32 PM, Yasuaki Ishimatsu
isimatu.yasu...@jp.fujitsu.com wrote:
 The function get_page_bootmem() may be called more than one time to the same
 page. There is no need to set page's type, private if the function is not
 the first time called to the page.

 Note: the patch is just optimization and does not fix any problem.

 CC: David Rientjes rient...@google.com
 CC: Jiang Liu liu...@gmail.com
 CC: Len Brown len.br...@intel.com
 CC: Christoph Lameter c...@linux.com
 Cc: Minchan Kim minchan@gmail.com
 CC: Andrew Morton a...@linux-foundation.org
 CC: KOSAKI Motohiro kosaki.motoh...@jp.fujitsu.com
 CC: Wen Congyang we...@cn.fujitsu.com
 Signed-off-by: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
 ---
  mm/memory_hotplug.c |   15 +++
  1 file changed, 11 insertions(+), 4 deletions(-)

 Index: linux-3.6/mm/memory_hotplug.c
 ===
 --- linux-3.6.orig/mm/memory_hotplug.c  2012-10-04 18:29:58.284676075 +0900
 +++ linux-3.6/mm/memory_hotplug.c   2012-10-04 18:30:03.454680542 +0900
 @@ -95,10 +95,17 @@ static void release_memory_resource(stru
  static void get_page_bootmem(unsigned long info,  struct page *page,
  unsigned long type)
  {
 -   page-lru.next = (struct list_head *) type;
 -   SetPagePrivate(page);
 -   set_page_private(page, info);
 -   atomic_inc(page-_count);
 +   unsigned long page_type;
 +
 +   page_type = (unsigned long)page-lru.next;

If I understand correctly, page-lru.next might be uninitialized yet.

Moreover, I have no seen any good effect in this patch. I don't understand
why we need to increase code complexity.



 +   if (page_type  MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
 +   page_type  MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE){
 +   page-lru.next = (struct list_head *)type;
 +   SetPagePrivate(page);
 +   set_page_private(page, info);
 +   atomic_inc(page-_count);
 +   } else
 +   atomic_inc(page-_count);
  }

  /* reference to __meminit __free_pages_bootmem is valid

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[PATCH 5/10] memory-hotplug : memory-hotplug: check page type in get_page_bootmem

2012-10-04 Thread Yasuaki Ishimatsu 
The function get_page_bootmem() may be called more than one time to the same
page. There is no need to set page's type, private if the function is not
the first time called to the page.

Note: the patch is just optimization and does not fix any problem.

CC: David Rientjes rient...@google.com
CC: Jiang Liu liu...@gmail.com
CC: Len Brown len.br...@intel.com
CC: Christoph Lameter c...@linux.com
Cc: Minchan Kim minchan@gmail.com
CC: Andrew Morton a...@linux-foundation.org
CC: KOSAKI Motohiro kosaki.motoh...@jp.fujitsu.com
CC: Wen Congyang we...@cn.fujitsu.com
Signed-off-by: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
---
 mm/memory_hotplug.c |   15 +++
 1 file changed, 11 insertions(+), 4 deletions(-)

Index: linux-3.6/mm/memory_hotplug.c
===
--- linux-3.6.orig/mm/memory_hotplug.c  2012-10-04 18:29:58.284676075 +0900
+++ linux-3.6/mm/memory_hotplug.c   2012-10-04 18:30:03.454680542 +0900
@@ -95,10 +95,17 @@ static void release_memory_resource(stru
 static void get_page_bootmem(unsigned long info,  struct page *page,
 unsigned long type)
 {
-   page-lru.next = (struct list_head *) type;
-   SetPagePrivate(page);
-   set_page_private(page, info);
-   atomic_inc(page-_count);
+   unsigned long page_type;
+
+   page_type = (unsigned long)page-lru.next;
+   if (page_type  MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
+   page_type  MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE){
+   page-lru.next = (struct list_head *)type;
+   SetPagePrivate(page);
+   set_page_private(page, info);
+   atomic_inc(page-_count);
+   } else
+   atomic_inc(page-_count);
 }
 
 /* reference to __meminit __free_pages_bootmem is valid

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