This is a note to let you know that I've just added the patch titled
memory hotplug: fix section info double registration bug
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
memory-hotplug-fix-section-info-double-registration-bug.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From f14851af0ebb32745c6c5a2e400aa0549f9d20df Mon Sep 17 00:00:00 2001
From: qiuxishi <[email protected]>
Date: Mon, 17 Sep 2012 14:09:24 -0700
Subject: memory hotplug: fix section info double registration bug
From: qiuxishi <[email protected]>
commit f14851af0ebb32745c6c5a2e400aa0549f9d20df upstream.
There may be a bug when registering section info. For example, on my
Itanium platform, the pfn range of node0 includes the other nodes, so
other nodes' section info will be double registered, and memmap's page
count will equal to 3.
node0: start_pfn=0x100, spanned_pfn=0x20fb00, present_pfn=0x7f8a3, =>
0x000100-0x20fc00
node1: start_pfn=0x80000, spanned_pfn=0x80000, present_pfn=0x80000, =>
0x080000-0x100000
node2: start_pfn=0x100000, spanned_pfn=0x80000, present_pfn=0x80000, =>
0x100000-0x180000
node3: start_pfn=0x180000, spanned_pfn=0x80000, present_pfn=0x80000, =>
0x180000-0x200000
free_all_bootmem_node()
register_page_bootmem_info_node()
register_page_bootmem_info_section()
When hot remove memory, we can't free the memmap's page because
page_count() is 2 after put_page_bootmem().
sparse_remove_one_section()
free_section_usemap()
free_map_bootmem()
put_page_bootmem()
[[email protected]: add code comment]
Signed-off-by: Xishi Qiu <[email protected]>
Signed-off-by: Jiang Liu <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
mm/memory_hotplug.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -116,9 +116,6 @@ static void register_page_bootmem_info_s
struct mem_section *ms;
struct page *page, *memmap;
- if (!pfn_valid(start_pfn))
- return;
-
section_nr = pfn_to_section_nr(start_pfn);
ms = __nr_to_section(section_nr);
@@ -177,9 +174,16 @@ void register_page_bootmem_info_node(str
end_pfn = pfn + pgdat->node_spanned_pages;
/* register_section info */
- for (; pfn < end_pfn; pfn += PAGES_PER_SECTION)
- register_page_bootmem_info_section(pfn);
-
+ for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+ /*
+ * Some platforms can assign the same pfn to multiple nodes - on
+ * node0 as well as nodeN. To avoid registering a pfn against
+ * multiple nodes we check that this pfn does not already
+ * reside in some other node.
+ */
+ if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node))
+ register_page_bootmem_info_section(pfn);
+ }
}
#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
Patches currently in stable-queue which might be from [email protected] are
queue-3.0/memory-hotplug-fix-section-info-double-registration-bug.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
