The patch titled Subject: mm: sparse: fix section usemap placement calculation has been removed from the -mm tree. Its filename was mm-sparse-fix-section-usemap-placement-calculation.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Yinghai Lu <yinghai@xxxxxxxxxx> Subject: mm: sparse: fix section usemap placement calculation 238305b ("mm: remove sparsemem allocation details from the bootmem allocator") introduced a bug in the allocation goal calculation that put section usemaps not in the same section as the node descriptors, creating unnecessary hotplug dependencies between them: [ 0.000000] node 0 must be removed before remove section 16399 [ 0.000000] node 1 must be removed before remove section 16399 [ 0.000000] node 2 must be removed before remove section 16399 [ 0.000000] node 3 must be removed before remove section 16399 [ 0.000000] node 4 must be removed before remove section 16399 [ 0.000000] node 5 must be removed before remove section 16399 [ 0.000000] node 6 must be removed before remove section 16399 The reason is that it applies PAGE_SECTION_MASK to the physical address of the node descriptor when finding a suitable place to put the usemap, when this mask is actually intended to be used with PFNs. Because the PFN mask is wider, the target address will point beyond the wanted section holding the node descriptor and the node must be offlined before the section holding the usemap can go. Fix this by extending the mask to address width before use. Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/sparse.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN mm/sparse.c~mm-sparse-fix-section-usemap-placement-calculation mm/sparse.c --- a/mm/sparse.c~mm-sparse-fix-section-usemap-placement-calculation +++ a/mm/sparse.c @@ -287,7 +287,7 @@ sparse_early_usemaps_alloc_pgdat_section * from the same section as the pgdat where possible to avoid * this problem. */ - goal = __pa(pgdat) & PAGE_SECTION_MASK; + goal = __pa(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT); host_pgdat = NODE_DATA(early_pfn_to_nid(goal >> PAGE_SHIFT)); return __alloc_bootmem_node_nopanic(host_pgdat, size, SMP_CACHE_BYTES, goal); _ Patches currently in -mm which might be from yinghai@xxxxxxxxxx are origin.patch linux-next.patch mm-memblockc-memblock_double_array-cosmetic-cleanups.patch mm-setup-pageblock_order-before-its-used-by-sparsemem.patch mm-hotplug-correctly-setup-fallback-zonelists-when-creating-new-pgdat.patch mm-hotplug-correctly-add-new-zone-to-all-other-nodes-zone-lists.patch mm-hotplug-free-zone-pageset-when-a-zone-becomes-empty.patch mm-hotplug-mark-memory-hotplug-code-in-page_allocc-as-__meminit.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