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authorYasunori Goto <y-goto@jp.fujitsu.com>2008-04-28 05:13:33 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-28 11:58:25 -0400
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')
-rw-r--r--mm/sparse.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/mm/sparse.c b/mm/sparse.c
index 5398d48c360a..08f053218ee8 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -249,11 +249,22 @@ static unsigned long *__kmalloc_section_usemap(void)
249 249
250static unsigned long *__init sparse_early_usemap_alloc(unsigned long pnum) 250static unsigned long *__init sparse_early_usemap_alloc(unsigned long pnum)
251{ 251{
252 unsigned long *usemap; 252 unsigned long *usemap, section_nr;
253 struct mem_section *ms = __nr_to_section(pnum); 253 struct mem_section *ms = __nr_to_section(pnum);
254 int nid = sparse_early_nid(ms); 254 int nid = sparse_early_nid(ms);
255 struct pglist_data *pgdat = NODE_DATA(nid);
255 256
256 usemap = alloc_bootmem_node(NODE_DATA(nid), usemap_size()); 257 /*
258 * Usemap's page can't be freed until freeing other sections
259 * which use it. And, Pgdat has same feature.
260 * If section A has pgdat and section B has usemap for other
261 * sections (includes section A), both sections can't be removed,
262 * because there is the dependency each other.
263 * To solve above issue, this collects all usemap on the same section
264 * which has pgdat.
265 */
266 section_nr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
267 usemap = alloc_bootmem_section(usemap_size(), section_nr);
257 if (usemap) 268 if (usemap)
258 return usemap; 269 return usemap;
259 270