The patch titled Subject: memory-hotplug, mm/sparse.c: clear the memory to store struct page has been added to the -mm tree. Its filename is memory-hotplug-mm-sparsec-clear-the-memory-to-store-struct-page.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Wen Congyang <wency@xxxxxxxxxxxxxx> Subject: memory-hotplug, mm/sparse.c: clear the memory to store struct page If sparse memory vmemmap is enabled, we can't free the memory to store struct page when a memory device is hotremoved, because we may store struct page in the memory to manage the memory which doesn't belong to this memory device. When we hotadded this memory device again, we will reuse this memory to store struct page, and struct page may contain some obsolete information, and we will get bad-page state: [ 59.611278] init_memory_mapping: [mem 0x80000000-0x9fffffff] [ 59.637836] Built 2 zonelists in Node order, mobility grouping on. Total pages: 547617 [ 59.638739] Policy zone: Normal [ 59.650840] BUG: Bad page state in process bash pfn:9b6dc [ 59.651124] page:ffffea0002200020 count:0 mapcount:0 mapping: (null) index:0xfdfdfdfdfdfdfdfd [ 59.651494] page flags: 0x2fdfdfdfd5df9fd(locked|referenced|uptodate|dirty|lru|active|slab|owner_priv_1|private|private_2|writeback|head|tail|swapcache|reclaim|swapbacked|unevictable|uncached|compound_lock) [ 59.653604] Modules linked in: netconsole acpiphp pci_hotplug acpi_memhotplug loop kvm_amd kvm microcode tpm_tis tpm tpm_bios evdev psmouse serio_raw i2c_piix4 i2c_core parport_pc parport processor button thermal_sys ext3 jbd mbcache sg sr_mod cdrom ata_generic virtio_net ata_piix virtio_blk libata virtio_pci virtio_ring virtio scsi_mod [ 59.656998] Pid: 988, comm: bash Not tainted 3.6.0-rc7-guest #12 [ 59.657172] Call Trace: [ 59.657275] [<ffffffff810e9b30>] ? bad_page+0xb0/0x100 [ 59.657434] [<ffffffff810ea4c3>] ? free_pages_prepare+0xb3/0x100 [ 59.657610] [<ffffffff810ea668>] ? free_hot_cold_page+0x48/0x1a0 [ 59.657787] [<ffffffff8112cc08>] ? online_pages_range+0x68/0xa0 [ 59.657961] [<ffffffff8112cba0>] ? __online_page_increment_counters+0x10/0x10 [ 59.658162] [<ffffffff81045561>] ? walk_system_ram_range+0x101/0x110 [ 59.658346] [<ffffffff814c4f95>] ? online_pages+0x1a5/0x2b0 [ 59.658515] [<ffffffff8135663d>] ? __memory_block_change_state+0x20d/0x270 [ 59.658710] [<ffffffff81356756>] ? store_mem_state+0xb6/0xf0 [ 59.658878] [<ffffffff8119e482>] ? sysfs_write_file+0xd2/0x160 [ 59.659052] [<ffffffff8113769a>] ? vfs_write+0xaa/0x160 [ 59.659212] [<ffffffff81137977>] ? sys_write+0x47/0x90 [ 59.659371] [<ffffffff814e2f25>] ? async_page_fault+0x25/0x30 [ 59.659543] [<ffffffff814ea239>] ? system_call_fastpath+0x16/0x1b [ 59.659720] Disabling lock debugging due to kernel taint This patch clears the memory to store struct page to avoid unexpected error. Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Jiang Liu <liuj97@xxxxxxxxx> Cc: Minchan Kim <minchan.kim@xxxxxxxxx> Acked-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx> Reported-by: Vasilis Liaskovitis <vasilis.liaskovitis@xxxxxxxxxxxxxxxx> Cc: Dave Hansen <dave@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/sparse.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff -puN mm/sparse.c~memory-hotplug-mm-sparsec-clear-the-memory-to-store-struct-page mm/sparse.c --- a/mm/sparse.c~memory-hotplug-mm-sparsec-clear-the-memory-to-store-struct-page +++ a/mm/sparse.c @@ -638,7 +638,6 @@ static struct page *__kmalloc_section_me got_map_page: ret = (struct page *)pfn_to_kaddr(page_to_pfn(page)); got_map_ptr: - memset(ret, 0, memmap_size); return ret; } @@ -760,6 +759,8 @@ int __meminit sparse_add_one_section(str goto out; } + memset(memmap, 0, sizeof(struct page) * nr_pages); + ms->section_mem_map |= SECTION_MARKED_PRESENT; ret = sparse_init_one_section(ms, section_nr, memmap, usemap); _ Patches currently in -mm which might be from wency@xxxxxxxxxxxxxx are cpu_hotplug-unmap-cpu2node-when-the-cpu-is-hotremoved.patch cpu_hotplug-unmap-cpu2node-when-the-cpu-is-hotremoved-fix.patch acpi_memhotplugc-fix-memory-leak-when-memory-device-is-unbound-from-the-module-acpi_memhotplug.patch acpi_memhotplugc-free-memory-device-if-acpi_memory_enable_device-failed.patch acpi_memhotplugc-remove-memory-info-from-list-before-freeing-it.patch acpi_memhotplugc-dont-allow-to-eject-the-memory-device-if-it-is-being-used.patch acpi_memhotplugc-bind-the-memory-device-when-the-driver-is-being-loaded.patch acpi_memhotplugc-auto-bind-the-memory-device-which-is-hotplugged-before-the-driver-is-loaded.patch x86-numa-dont-check-if-node-is-numa_no_node.patch x86-make-mem=-option-to-work-for-efi-platform.patch memory-hotplug-suppress-device-memoryx-does-not-have-a-release-function-warning.patch memory-hotplug-skip-hwpoisoned-page-when-offlining-pages.patch memory-hotplug-update-mce_bad_pages-when-removing-the-memory.patch memory-hotplug-update-mce_bad_pages-when-removing-the-memory-fix.patch memory-hotplug-auto-offline-page_cgroup-when-onlining-memory-block-failed.patch memory-hotplug-fix-nr_free_pages-mismatch.patch numa-convert-static-memory-to-dynamically-allocated-memory-for-per-node-device.patch memory-hotplug-suppress-device-nodex-does-not-have-a-release-function-warning.patch memory-hotplug-mm-sparsec-clear-the-memory-to-store-struct-page.patch memory-hotplug-allocate-zones-pcp-before-onlining-pages.patch memory-hotplug-allocate-zones-pcp-before-onlining-pages-fix.patch memory-hotplug-allocate-zones-pcp-before-onlining-pages-fix-2.patch memory_hotplug-fix-possible-incorrect-node_states.patch slub-hotplug-ignore-unrelated-nodes-hot-adding-and-hot-removing.patch documentation-kernel-parameterstxt-update-mem=-options-spec-according-to-its-implementation.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