FYI, we noticed the below changes on git://internal_merge_and_test_tree devel-catchup-201512220028 commit 26efb85d35c71bc297e22773928062c97e41a8a2 ("blk-mq: dynamic h/w context count") +------------------------------------------------+------------+------------+ | | e56dda0be8 | 26efb85d35 | +------------------------------------------------+------------+------------+ | boot_successes | 15 | 2 | | boot_failures | 0 | 12 | | BUG_kmalloc-#(Not_tainted):Poison_overwritten | 0 | 8 | | INFO:#-#.First_byte#instead_of | 0 | 12 | | INFO:Slab#objects=#used=#fp=0x(null)flags= | 0 | 12 | | INFO:Object#@offset=#fp= | 0 | 12 | | backtrace:init | 0 | 12 | | backtrace:kernel_init_freeable | 0 | 12 | | BUG_kmalloc-#(Not_tainted):Redzone_overwritten | 0 | 4 | | BUG_kmalloc-#(Tainted:G_B):Redzone_overwritten | 0 | 4 | | backtrace:vp_find_vqs | 0 | 4 | | backtrace:init_vq | 0 | 4 | | backtrace:ide_host_alloc | 0 | 4 | | backtrace:ide_pci_init_two | 0 | 4 | | backtrace:ide_pci_init_one | 0 | 4 | | backtrace:piix_init_one | 0 | 4 | | backtrace:ide_scan_pcibus | 0 | 4 | +------------------------------------------------+------------+------------+ [ 14.781818] brd: module loaded [ 14.818921] loop: module loaded [ 18.033239] ============================================================================= [ 18.035280] BUG kmalloc-512 (Not tainted): Redzone overwritten [ 18.036486] ----------------------------------------------------------------------------- [ 18.036486] [ 18.039089] Disabling lock debugging due to kernel taint [ 18.040287] INFO: 0xffff88007e0b55b0-0xffff88007e0b55b7. First byte 0x0 instead of 0xbb [ 18.042289] INFO: Slab 0xffffea0001f82d00 objects=19 used=19 fp=0x (null) flags=0x100000000004080 [ 18.044496] INFO: Object 0xffff88007e0b53b0 @offset=5040 fp=0xffff88007e0b56f8 [ 18.044496] [ 18.046957] Bytes b4 ffff88007e0b53a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.049075] Object ffff88007e0b53b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.051240] Object ffff88007e0b53c0: 21 43 65 87 00 00 00 00 00 00 00 00 00 00 00 00 !Ce............. [ 18.053370] Object ffff88007e0b53d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.055466] Object ffff88007e0b53e0: 00 00 00 00 00 00 00 00 21 43 65 87 00 00 00 00 ........!Ce..... [ 18.057562] Object ffff88007e0b53f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.059653] Object ffff88007e0b5400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.061817] Object ffff88007e0b5410: 21 43 65 87 00 00 00 00 00 00 00 00 00 00 00 00 !Ce............. [ 18.063933] Object ffff88007e0b5420: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.066024] Object ffff88007e0b5430: 00 00 00 00 00 00 00 00 21 43 65 87 00 00 00 00 ........!Ce..... [ 18.068141] Object ffff88007e0b5440: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.070246] Object ffff88007e0b5450: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.072341] Object ffff88007e0b5460: 21 43 65 87 00 00 00 00 00 00 00 00 00 00 00 00 !Ce............. [ 18.074462] Object ffff88007e0b5470: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.076561] Object ffff88007e0b5480: 00 00 00 00 00 00 00 00 21 43 65 87 00 00 00 00 ........!Ce..... [ 18.078663] Object ffff88007e0b5490: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.080804] Object ffff88007e0b54a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.082917] Object ffff88007e0b54b0: 21 43 65 87 00 00 00 00 00 00 00 00 00 00 00 00 !Ce............. [ 18.085004] Object ffff88007e0b54c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.087129] Object ffff88007e0b54d0: 00 00 00 00 00 00 00 00 21 43 65 87 00 00 00 00 ........!Ce..... [ 18.089217] Object ffff88007e0b54e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.091373] Object ffff88007e0b54f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.093455] Object ffff88007e0b5500: 21 43 65 87 00 00 00 00 00 00 00 00 00 00 00 00 !Ce............. [ 18.095548] Object ffff88007e0b5510: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.097645] Object ffff88007e0b5520: 00 00 00 00 00 00 00 00 21 43 65 87 00 00 00 00 ........!Ce..... [ 18.099755] Object ffff88007e0b5530: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.101861] Object ffff88007e0b5540: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.103941] Object ffff88007e0b5550: 21 43 65 87 00 00 00 00 00 00 00 00 00 00 00 00 !Ce............. [ 18.106079] Object ffff88007e0b5560: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.108176] Object ffff88007e0b5570: 00 00 00 00 00 00 00 00 21 43 65 87 00 00 00 00 ........!Ce..... [ 18.110287] Object ffff88007e0b5580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.112393] Object ffff88007e0b5590: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 18.114497] Object ffff88007e0b55a0: 21 43 65 87 00 00 00 00 00 00 00 00 00 00 00 00 !Ce............. [ 18.116568] Redzone ffff88007e0b55b0: 00 00 00 00 00 00 00 00 ........ [ 18.118599] Padding ffff88007e0b56f0: 00 00 00 00 00 00 00 00 ........ [ 18.120625] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G B 4.4.0-rc2-00145-g26efb85 #1 [ 18.122636] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 18.124670] 0000000000000000 ffff88007570b680 ffffffff81504f45 ffff880075c02b40 [ 18.126801] ffff88007570b6b0 ffffffff811c0c1e ffff88007e0b55b0 00000000000000bb [ 18.128935] ffff880075c02b40 ffff88007e0b55b7 ffff88007570b708 ffffffff811c0cc9 [ 18.131113] Call Trace: [ 18.131932] [] dump_stack+0x4b/0x63 [ 18.133074] [] print_trailer+0x127/0x130 [ 18.134312] [] check_bytes_and_report+0xa2/0xea [ 18.135625] [] check_object+0x45/0x1f7 [ 18.136801] [] ? alloc_desc+0x31/0x1a4 [ 18.137980] [] alloc_debug_processing+0xdc/0x14b [ 18.139278] [] ___slab_alloc+0x485/0x612 [ 18.140494] [] ? alloc_desc+0x31/0x1a4 [ 18.141707] [] ? deactivate_slab+0x4da/0x516 [ 18.142930] [] ? __lock_is_held+0x3c/0x57 [ 18.144140] [] ? alloc_desc+0x31/0x1a4 [ 18.145350] [] __slab_alloc+0x4f/0x83 [ 18.146501] [] ? __slab_alloc+0x4f/0x83 [ 18.147713] [] ? alloc_desc+0x31/0x1a4 [ 18.148879] [] ? alloc_desc+0x31/0x1a4 [ 18.150053] [] kmem_cache_alloc_node_trace+0x91/0x234 [ 18.151445] [] ? trace_hardirqs_on_caller+0x17d/0x199 [ 18.152774] [] alloc_desc+0x31/0x1a4 [ 18.153934] [] __irq_alloc_descs+0xf4/0x1a3 [ 18.155171] [] irq_domain_alloc_descs+0x4c/0x72 [ 18.156443] [] __irq_domain_alloc_irqs+0x81/0x22b [ 18.157760] [] ? local_clock+0x20/0x22 [ 18.158914] [] msi_domain_alloc_irqs+0xa7/0x14b [ 18.160217] [] pci_msi_domain_alloc_irqs+0x15/0x17 [ 18.161546] [] native_setup_msi_irqs+0x50/0x5b [ 18.162798] [] arch_setup_msi_irqs+0xf/0x11 [ 18.164023] [] pci_msi_setup_msi_irqs+0x4e/0x52 [ 18.165357] [] pci_enable_msix+0x225/0x36e [ 18.178254] [] pci_enable_msix_range+0x31/0x50 [ 18.179515] [] vp_request_msix_vectors+0xbf/0x1e1 [ 18.180836] [] vp_try_to_find_vqs+0xe6/0x318 [ 18.182067] [] ? vsnprintf+0x376/0x3af [ 18.183226] [] vp_find_vqs+0x2e/0x81 [ 18.184458] [] init_vq+0x162/0x201 [ 18.185591] [] ? virtblk_probe+0xc5/0x641 [ 18.186797] [] virtblk_probe+0x13d/0x641 [ 18.188004] [] ? devices_kset_move_last+0x57/0x5c [ 18.189298] [] virtio_dev_probe+0x111/0x187 [ 18.190537] [] driver_probe_device+0xf7/0x250 [ 18.191790] [] __driver_attach+0x61/0x83 [ 18.192972] [] ? driver_probe_device+0x250/0x250 [ 18.194274] [] bus_for_each_dev+0x6f/0x87 [ 18.195474] [] driver_attach+0x1e/0x20 [ 18.196632] [] bus_add_driver+0xf2/0x1e4 [ 18.197838] [] ? init_cryptoloop+0x28/0x28 [ 18.199032] [] driver_register+0x8a/0xc6 [ 18.200242] [] ? init_cryptoloop+0x28/0x28 [ 18.201475] [] register_virtio_driver+0x2b/0x2d [ 18.202722] [] init+0x5a/0x87 [ 18.203800] [] do_one_initcall+0xe7/0x177 [ 18.205010] [] kernel_init_freeable+0x1c2/0x24a [ 18.206273] [] ? rest_init+0x140/0x140 [ 18.207453] [] kernel_init+0xe/0xd4 [ 18.208600] [] ret_from_fork+0x3f/0x70 [ 18.209764] [] ? rest_init+0x140/0x140 [ 18.210958] FIX kmalloc-512: Restoring 0xffff88007e0b55b0-0xffff88007e0b55b7=0xbb [ 18.210958] [ 18.213431] FIX kmalloc-512: Marking all objects used Thanks, Kernel Test Robot