The patch titled Subject: memory hotplug: fix section info double registration bug has been removed from the -mm tree. Its filename was memory-hotplug-fix-a-double-register-section-info-bug.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: qiuxishi <qiuxishi@xxxxxxxxx> Subject: memory hotplug: fix section info double registration bug There may be a bug when registering section info. For example, on my Itanium platform, the pfn range of node0 includes the other nodes, so other nodes' section info will be double registered, and memmap's page count will equal to 3. node0: start_pfn=0x100, spanned_pfn=0x20fb00, present_pfn=0x7f8a3, => 0x000100-0x20fc00 node1: start_pfn=0x80000, spanned_pfn=0x80000, present_pfn=0x80000, => 0x080000-0x100000 node2: start_pfn=0x100000, spanned_pfn=0x80000, present_pfn=0x80000, => 0x100000-0x180000 node3: start_pfn=0x180000, spanned_pfn=0x80000, present_pfn=0x80000, => 0x180000-0x200000 free_all_bootmem_node() register_page_bootmem_info_node() register_page_bootmem_info_section() When hot remove memory, we can't free the memmap's page because page_count() is 2 after put_page_bootmem(). sparse_remove_one_section() free_section_usemap() free_map_bootmem() put_page_bootmem() [akpm@xxxxxxxxxxxxxxxxxxxx: add code comment] Signed-off-by: Xishi Qiu <qiuxishi@xxxxxxxxxx> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx> Acked-by: Mel Gorman <mgorman@xxxxxxx> Cc: "Luck, Tony" <tony.luck@xxxxxxxxx> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory_hotplug.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff -puN mm/memory_hotplug.c~memory-hotplug-fix-a-double-register-section-info-bug mm/memory_hotplug.c --- a/mm/memory_hotplug.c~memory-hotplug-fix-a-double-register-section-info-bug +++ a/mm/memory_hotplug.c @@ -126,9 +126,6 @@ static void register_page_bootmem_info_s struct mem_section *ms; struct page *page, *memmap; - if (!pfn_valid(start_pfn)) - return; - section_nr = pfn_to_section_nr(start_pfn); ms = __nr_to_section(section_nr); @@ -187,9 +184,16 @@ void register_page_bootmem_info_node(str end_pfn = pfn + pgdat->node_spanned_pages; /* register_section info */ - for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) - register_page_bootmem_info_section(pfn); - + for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + /* + * Some platforms can assign the same pfn to multiple nodes - on + * node0 as well as nodeN. To avoid registering a pfn against + * multiple nodes we check that this pfn does not already + * reside in some other node. + */ + if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node)) + register_page_bootmem_info_section(pfn); + } } #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ _ Patches currently in -mm which might be from qiuxishi@xxxxxxxxx are origin.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