path: root/mm
diff options
authorYasunori Goto <y-goto@jp.fujitsu.com>2008-04-28 02:13:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-28 08:58:25 -0700
commit86f6dae1377523689bd8468fed2f2dd180fc0560 (patch)
tree90c4495ae947627d610f13c8a185fd16358bc14e /mm
parente70260aabea3af2a84b951e75166dcebe689b88e (diff)
memory hotplug: allocate usemap on the section with pgdat
Usemaps are allocated on the section which has pgdat by this. Because usemap size is very small, many other sections usemaps are allocated on only one page. If a section has usemap, it can't be removed until removing other sections. This dependency is not desirable for memory removing. Pgdat has similar feature. When a section has pgdat area, it must be the last section for removing on the node. So, if section A has pgdat and section B has usemap for section A, Both sections can't be removed due to dependency each other. To solve this issue, this patch collects usemap on same section with pgdat. If other sections doesn't have any dependency, this section will be able to be removed finally. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
1 files changed, 13 insertions, 2 deletions
diff --git a/mm/sparse.c b/mm/sparse.c
index 5398d48c360..08f053218ee 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -249,11 +249,22 @@ static unsigned long *__kmalloc_section_usemap(void)
static unsigned long *__init sparse_early_usemap_alloc(unsigned long pnum)
- unsigned long *usemap;
+ unsigned long *usemap, section_nr;
struct mem_section *ms = __nr_to_section(pnum);
int nid = sparse_early_nid(ms);
+ struct pglist_data *pgdat = NODE_DATA(nid);
- usemap = alloc_bootmem_node(NODE_DATA(nid), usemap_size());
+ /*
+ * Usemap's page can't be freed until freeing other sections
+ * which use it. And, Pgdat has same feature.
+ * If section A has pgdat and section B has usemap for other
+ * sections (includes section A), both sections can't be removed,
+ * because there is the dependency each other.
+ * To solve above issue, this collects all usemap on the same section
+ * which has pgdat.
+ */
+ section_nr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
+ usemap = alloc_bootmem_section(usemap_size(), section_nr);
if (usemap)
return usemap;