The patch titled memory hotplug)allocat: usemap on the section with pgdat has been removed from the -mm tree. Its filename was memory-hotplugallocate-usemap-on-the-section-with-pgdat.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: memory hotplug)allocat: usemap on the section with pgdat From: Yasunori Goto <y-goto@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx> Cc: Badari Pulavarty <pbadari@xxxxxxxxxx> Cc: Yinghai Lu <yhlu.kernel@xxxxxxxxx> Cc: Yasunori Goto <y-goto@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/sparse.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff -puN mm/sparse.c~memory-hotplugallocate-usemap-on-the-section-with-pgdat mm/sparse.c --- a/mm/sparse.c~memory-hotplugallocate-usemap-on-the-section-with-pgdat +++ a/mm/sparse.c @@ -249,11 +249,22 @@ static unsigned long *__kmalloc_section_ 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; _ Patches currently in -mm which might be from y-goto@xxxxxxxxxxxxxx are origin.patch powerpc-hotplug-memory-notifications-for-ppc.patch powerpc-update-lmb-for-hotplug-memory-add-remove.patch powerpc-provide-walk_memory_resource-for-ppc.patch ipc-scale-msgmni-to-the-amount-of-lowmem.patch ipc-scale-msgmni-to-the-number-of-ipc-namespaces.patch ipc-define-the-slab_memory_callback-priority-as-a-constant.patch ipc-recompute-msgmni-on-memory-add--remove.patch ipc-invoke-the-ipcns-notifier-chain-as-a-work-item.patch ipc-recompute-msgmni-on-ipc-namespace-creation-removal.patch ipc-do-not-recompute-msgmni-anymore-if-explicitly-set-by-user.patch ipc-re-enable-msgmni-automatic-recomputing-msgmni-if-set-to-negative.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html