At 10/19/2012 08:49 AM, Yasuaki Ishimatsu Wrote:

Hi Kosaki,

Sorry for late reply.

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

quoted

On Thu, Oct 4, 2012 at 10:32 PM, Yasuaki Ishimatsu
[off-list ref] wrote:

quoted

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 <rientjes@google.com>
CC: Jiang Liu <redacted>
CC: Len Brown <redacted>
CC: Christoph Lameter <redacted>
Cc: Minchan Kim <redacted>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: KOSAKI Motohiro <redacted>
CC: Wen Congyang <redacted>
Signed-off-by: Yasuaki Ishimatsu <redacted>
---
  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   

quoted

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

quoted

+       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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