[ 008/108] memory hotplug: fix section info double registration bug
3.2-stable review patch. If anyone has any objections, please let me know.
--
From: qiuxishi
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=0x8, spanned_pfn=0x8, present_pfn=0x8, =>
0x08-0x10
node2: start_pfn=0x10, spanned_pfn=0x8, present_pfn=0x8, =>
0x10-0x18
node3: start_pfn=0x18, spanned_pfn=0x8, present_pfn=0x8, =>
0x18-0x20
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()
[a...@linux-foundation.org: add code comment]
Signed-off-by: Xishi Qiu
Signed-off-by: Jiang Liu
Acked-by: Mel Gorman
Cc: "Luck, Tony"
Cc: Yasuaki Ishimatsu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
Signed-off-by: Ben Hutchings
---
mm/memory_hotplug.c | 16 ++--
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 3ad25f9..6a5b90d 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -126,9 +126,6 @@ static void register_page_bootmem_info_section(unsigned
long start_pfn)
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);
@@ -187,9 +184,16 @@ void register_page_bootmem_info_node(struct pglist_data
*pgdat)
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 */
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[ 008/108] memory hotplug: fix section info double registration bug
3.2-stable review patch. If anyone has any objections, please let me know.
--
From: qiuxishi qiuxi...@gmail.com
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=0x8, spanned_pfn=0x8, present_pfn=0x8, =
0x08-0x10
node2: start_pfn=0x10, spanned_pfn=0x8, present_pfn=0x8, =
0x10-0x18
node3: start_pfn=0x18, spanned_pfn=0x8, present_pfn=0x8, =
0x18-0x20
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()
[a...@linux-foundation.org: add code comment]
Signed-off-by: Xishi Qiu qiuxi...@huawei.com
Signed-off-by: Jiang Liu jiang@huawei.com
Acked-by: Mel Gorman mgor...@suse.de
Cc: Luck, Tony tony.l...@intel.com
Cc: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
Signed-off-by: Andrew Morton a...@linux-foundation.org
Signed-off-by: Linus Torvalds torva...@linux-foundation.org
Signed-off-by: Ben Hutchings b...@decadent.org.uk
---
mm/memory_hotplug.c | 16 ++--
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 3ad25f9..6a5b90d 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -126,9 +126,6 @@ static void register_page_bootmem_info_section(unsigned
long start_pfn)
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);
@@ -187,9 +184,16 @@ void register_page_bootmem_info_node(struct pglist_data
*pgdat)
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 */
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
