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| author | Zhang Yanfei <zhangyanfei@cn.fujitsu.com> | 2013-11-12 15:07:43 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-13 12:09:06 +0900 |
| commit | 81556b02525181e19ef073a798ba9d48db96f708 (patch) | |
| tree | b052b2fa8c92c80885245c3e13b6ef1ec4304fc1 /mm/sparse.c | |
| parent | 85b35feaecd4d2284505b22708795bc1f03fc897 (diff) | |
| download | lwn-81556b02525181e19ef073a798ba9d48db96f708.tar.gz lwn-81556b02525181e19ef073a798ba9d48db96f708.zip | |
mm/sparsemem: fix a bug in free_map_bootmem when CONFIG_SPARSEMEM_VMEMMAP
We pass the number of pages which hold page structs of a memory section
to free_map_bootmem(). This is right when !CONFIG_SPARSEMEM_VMEMMAP but
wrong when CONFIG_SPARSEMEM_VMEMMAP. When CONFIG_SPARSEMEM_VMEMMAP, we
should pass the number of pages of a memory section to free_map_bootmem.
So the fix is removing the nr_pages parameter. When
CONFIG_SPARSEMEM_VMEMMAP, we directly use the prefined marco
PAGES_PER_SECTION in free_map_bootmem. When !CONFIG_SPARSEMEM_VMEMMAP,
we calculate page numbers needed to hold the page structs for a memory
section and use the value in free_map_bootmem().
This was found by reading the code. And I have no machine that support
memory hot-remove to test the bug now.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/sparse.c')
| -rw-r--r-- | mm/sparse.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/mm/sparse.c b/mm/sparse.c index fbb9dbc6aca9..8cc7be0e9590 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -603,10 +603,10 @@ static void __kfree_section_memmap(struct page *memmap) vmemmap_free(start, end); } #ifdef CONFIG_MEMORY_HOTREMOVE -static void free_map_bootmem(struct page *memmap, unsigned long nr_pages) +static void free_map_bootmem(struct page *memmap) { unsigned long start = (unsigned long)memmap; - unsigned long end = (unsigned long)(memmap + nr_pages); + unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION); vmemmap_free(start, end); } @@ -648,12 +648,15 @@ static void __kfree_section_memmap(struct page *memmap) } #ifdef CONFIG_MEMORY_HOTREMOVE -static void free_map_bootmem(struct page *memmap, unsigned long nr_pages) +static void free_map_bootmem(struct page *memmap) { unsigned long maps_section_nr, removing_section_nr, i; - unsigned long magic; + unsigned long magic, nr_pages; struct page *page = virt_to_page(memmap); + nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) + >> PAGE_SHIFT; + for (i = 0; i < nr_pages; i++, page++) { magic = (unsigned long) page->lru.next; @@ -756,7 +759,6 @@ static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) static void free_section_usemap(struct page *memmap, unsigned long *usemap) { struct page *usemap_page; - unsigned long nr_pages; if (!usemap) return; @@ -777,12 +779,8 @@ static void free_section_usemap(struct page *memmap, unsigned long *usemap) * on the section which has pgdat at boot time. Just keep it as is now. */ - if (memmap) { - nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) - >> PAGE_SHIFT; - - free_map_bootmem(memmap, nr_pages); - } + if (memmap) + free_map_bootmem(memmap); } void sparse_remove_one_section(struct zone *zone, struct mem_section *ms) |