At 09/27/2012 12:58 AM, Vasilis Liaskovitis Wrote: > Testing 3.6.0-rc7 with this v9 patchset plus more recent fixes [1],[2],[3] > Running in a guest (qemu+seabios from [4]). > CONFIG_SLAB=y > CONFIG_DEBUG_SLAB=y > > - succesfull hot-add and online > - succesfull hot-remove with SCI (qemu) eject > - attempt to hot-readd same memory > > When the pages are re-onlined on hot-readd, I get a bad_page state for many > pages e.g. > > [ 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 > > Patch 20/21 deals with a similar scenario, but only for __PG_HWPOISON flag. > Did i miss any other patch for this? Please try the following patch: >From a38ec678e0a9b48b252f457d7910b7527049dc43 Mon Sep 17 00:00:00 2001 From: Wen Congyang <wency@xxxxxxxxxxxxxx> Date: Thu, 27 Sep 2012 17:27:57 +0800 Subject: [PATCH] clear the memory to store page information --- mm/sparse.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/mm/sparse.c b/mm/sparse.c index ab9d755..36dda08 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -639,7 +639,6 @@ static struct page *__kmalloc_section_memmap(unsigned long nr_pages) got_map_page: ret = (struct page *)pfn_to_kaddr(page_to_pfn(page)); got_map_ptr: - memset(ret, 0, memmap_size); return ret; } @@ -761,6 +760,8 @@ int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn, 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); -- 1.7.1 Thanks Wen Congyang > > thanks, > > - Vasilis > > [1] https://lkml.org/lkml/2012/9/6/635 > [2] https://lkml.org/lkml/2012/9/11/542 > [3] https://lkml.org/lkml/2012/9/20/37 > [4] http://permalink.gmane.org/gmane.comp.emulators.kvm.devel/98691 > > > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>