The patch titled
memory_hotplug: always initialize pageblock bitmap.
has been added to the -mm tree. Its filename is
memory_hotplug-always-initialize-pageblock-bitmap.patch
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------------------------------------------------------
Subject: memory_hotplug: always initialize pageblock bitmap.
From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Trying to online a new memory section that was added via memory hotplug
sometimes results in crashes when the new pages are added via __free_page.
Reason for that is that the pageblock bitmap isn't initialized and hence
contains random stuff. That means that get_pageblock_migratetype() returns
also random stuff and therefore
list_add(&page->lru,
&zone->free_area[order].free_list[migratetype]);
in __free_one_page() tries to do a list_add to something that isn't even
necessarily a list.
This is only an issue for memory sections that get added after boot time since
all previously present memory sections allocate their pageblock bitmaps via
the bootmem allocator which in turn initializes just everything it returns.
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Andy Whitcroft <apw@xxxxxxxxxxxx>
Cc: Dave Hansen <haveblue@xxxxxxxxxx>
Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Yasunori Goto <y-goto@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/sparse.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN mm/sparse.c~memory_hotplug-always-initialize-pageblock-bitmap mm/sparse.c
--- a/mm/sparse.c~memory_hotplug-always-initialize-pageblock-bitmap
+++ a/mm/sparse.c
@@ -244,7 +244,7 @@ unsigned long usemap_size(void)
#ifdef CONFIG_MEMORY_HOTPLUG
static unsigned long *__kmalloc_section_usemap(void)
{
- return kmalloc(usemap_size(), GFP_KERNEL);
+ return kzalloc(usemap_size(), GFP_KERNEL);
}
#endif /* CONFIG_MEMORY_HOTPLUG */
_
Patches currently in -mm which might be from heiko.carstens@xxxxxxxxxx are
origin.patch
linux-next.patch
memory-hotplug-memmap_init_zone-called-twice.patch
memory_hotplug-always-initialize-pageblock-bitmap.patch
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