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>
diff --git a/mm/sparse.c b/mm/sparse.c
index fbb9dbc..8cc7be0 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -603,10 +603,10 @@
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 @@
}
#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 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 @@
* 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)