FYI, we noticed the following commit (built with gcc-6): commit: c02c58dab2480ec45dc43e1e10970d763e6b7f1f ("[PATCH 06/15] blkcg: always associate a bio with a blkg") url: https://github.com/0day-ci/linux/commits/Dennis-Zhou/blkcg-ref-count-refactor-cleanup-blkcg-avg_lat/20180831-161742 base: https://git.kernel.org/cgit/linux/kernel/git/axboe/linux-block.git for-next in testcase: trinity with following parameters: runtime: 300s test-description: Trinity is a linux system call fuzz tester. test-url: http://codemonkey.org.uk/projects/trinity/ on test machine: qemu-system-x86_64 -enable-kvm -cpu host -smp 2 -m 1G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +------------------------------------------------------------------+------------+------------+ | | 1a3eeea831 | c02c58dab2 | +------------------------------------------------------------------+------------+------------+ | boot_successes | 6 | 0 | | boot_failures | 6 | 16 | | invoked_oom-killer:gfp_mask=0x | 4 | 6 | | Mem-Info | 5 | 9 | | Kernel_panic-not_syncing:Out_of_memory_and_no_killable_processes | 4 | 6 | | Out_of_memory:Kill_process | 2 | 3 | | WARNING:at_block/blk-throttle.c:#blk_throtl_bio | 0 | 10 | | RIP:blk_throtl_bio | 0 | 10 | +------------------------------------------------------------------+------------+------------+ [ 120.023103] WARNING: CPU: 1 PID: 1 at block/blk-throttle.c:2149 blk_throtl_bio+0xdaf/0x2490 [ 120.051033] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc1-00168-gc02c58d #1 [ 120.074200] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 120.100912] RIP: 0010:blk_throtl_bio+0xdaf/0x2490 [ 120.114291] Code: 08 84 d2 0f 85 1a 13 00 00 66 41 81 4f 14 00 02 e9 ed f3 ff ff 48 83 05 ce 31 ff 05 01 e9 f3 fb ff ff 48 83 05 39 45 ff 05 01 <0f> 0b 48 83 05 37 45 ff 05 01 e9 25 f3 ff ff 49 8d bf 28 02 00 00 [ 120.167531] RSP: 0000:ffff880030e36fd0 EFLAGS: 00010202 [ 120.184191] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 120.204216] RDX: 0000000000000000 RSI: ffffffffa72f04c0 RDI: 0000000000000206 [ 120.224215] RBP: ffff880030e370a0 R08: 0000000002384946 R09: 00000000023a2d90 [ 120.247539] R10: ffffed00062bc4fa R11: ffff8800315e27d3 R12: ffff880030f60150 [ 120.267576] R13: ffff88001c7a5b00 R14: ffff880030794400 R15: ffff880030f60140 [ 120.287560] FS: 0000000000000000(0000) GS:ffff880031400000(0000) knlGS:0000000000000000 [ 120.314198] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 120.330963] CR2: 0000000000000000 CR3: 000000000fc6d000 CR4: 00000000000006a0 [ 120.350859] Call Trace: [ 120.360930] ? bio_associate_create_blkg+0x30d/0x950 [ 120.374222] ? reacquire_held_locks+0x400/0x400 [ 120.387606] ? bio_associate_blkg+0x240/0x240 [ 120.404166] ? do_raw_spin_unlock+0x16a/0x2d0 [ 120.417570] ? _raw_spin_unlock+0x5c/0xa0 [ 120.430924] generic_make_request_checks+0x8fa/0x14b0 [ 120.444270] ? percpu_ref_put_many+0x1c0/0x1c0 [ 120.460957] ? kasan_check_write+0x24/0x30 [ 120.474243] ? sched_clock_local+0x99/0x1c0 [ 120.487567] generic_make_request+0x237/0xdf0 [ 120.500949] ? sched_clock_cpu+0x20c/0x2a0 [ 120.514268] ? blk_plug_queued_count+0x180/0x180 [ 120.530925] ? debug_smp_processor_id+0x1f/0x30 [ 120.544243] submit_bio+0x2a0/0x410 [ 120.557564] ? submit_bio+0x2a0/0x410 [ 120.568470] ? lock_acquire+0x112/0x1d0 [ 120.580903] ? guard_bio_eod+0xb0/0x420 [ 120.590936] ? direct_make_request+0x240/0x240 [ 120.607501] ? guard_bio_eod+0x1b6/0x420 [ 120.617592] ? bio_add_page+0xd0/0x100 [ 120.630913] submit_bh_wbc+0x526/0x840 [ 120.640978] ? unlock_buffer+0x40/0x40 [ 120.654304] block_read_full_page+0x807/0xba0 [ 120.667591] ? bh_submit_read+0x240/0x240 [ 120.673290] ? create_page_buffers+0x210/0x210 [ 120.691014] ? add_to_page_cache_locked+0x20/0x20 [ 120.707532] ? alloc_page_interleave+0x139/0x1b0 [ 120.724230] ? __next_node_in+0x59/0x70 [ 120.734304] blkdev_readpage+0x1b/0x30 [ 120.747597] do_read_cache_page+0x795/0x1150 [ 120.760923] ? blkdev_writepages+0x20/0x20 [ 120.774234] ? kasan_unpoison_shadow+0x3d/0x60 [ 120.787530] ? preempt_count_add+0x159/0x210 [ 120.800913] ? pagecache_get_page+0x6f0/0x6f0 [ 120.814162] ? __this_cpu_preempt_check+0x1b/0x30 [ 120.830921] ? kasan_unpoison_shadow+0x3d/0x60 [ 120.844270] ? kasan_alloc_pages+0x40/0x50 [ 120.857909] ? get_page_from_freelist+0x2023/0x33b0 [ 120.870909] read_cache_page+0x53/0x90 [ 120.884132] read_dev_sector+0xc8/0x2c0 [ 120.897509] ? set_info+0x110/0x110 [ 120.907509] msdos_partition+0x231/0x2610 [ 120.920894] ? memcpy+0x6d/0x80 [ 120.930915] ? vsnprintf+0x96f/0x1cf0 [ 120.944176] ? set_info+0x110/0x110 [ 120.984325] ? snprintf+0x8f/0xb0 [ 120.997559] ? snprintf+0x8f/0xb0 [ 121.007498] ? vscnprintf+0x40/0x40 [ 121.017520] ? __next_node_in+0x59/0x70 [ 121.030968] ? set_info+0x110/0x110 [ 121.044221] ? set_info+0x110/0x110 [ 121.057506] check_partition+0x3db/0x7d0 [ 121.070920] rescan_partitions+0x192/0xac0 [ 121.080900] ? __might_sleep+0xad/0x1e0 [ 121.094193] ? bd_set_size+0x305/0x3c0 [ 121.107505] __blkdev_get+0x8c3/0x13b0 [ 121.117547] ? bd_set_size+0x3c0/0x3c0 [ 121.130907] ? debug_smp_processor_id+0x1f/0x30 [ 121.144195] blkdev_get+0x41c/0x9f0 [ 121.157679] ? refcount_sub_and_test_checked+0x100/0x1e0 [ 121.170883] ? __blkdev_get+0x13b0/0x13b0 [ 121.184233] ? do_raw_spin_unlock+0x16a/0x2d0 [ 121.197551] ? refcount_dec_and_test_checked+0x19/0x30 [ 121.214214] ? kobject_put+0x61/0x5a0 [ 121.227913] __device_add_disk+0xfc6/0x12d0 [ 121.241719] ? lock_acquire+0x112/0x1d0 [ 121.254191] ? bdget_disk+0xb0/0xb0 [ 121.291132] ? lockdep_init_map+0x11/0x20 [ 121.304263] ? lockdep_init_map+0x11/0x20 [ 121.317606] ? __raw_spin_lock_init+0x3d/0x120 [ 121.331152] ? device_initialize+0x2d3/0x3e0 [ 121.344254] device_add_disk+0x16/0x20 [ 121.357510] null_add_dev+0xcd5/0x1fe0 [ 121.370892] null_init+0x4cb/0x6c6 [ 121.380903] ? pkt_init+0x578/0x578 [ 121.394231] do_one_initcall+0x191/0x3f3 [ 121.407482] ? start_kernel+0xa52/0xa52 [ 121.417522] ? kasan_unpoison_shadow+0x3d/0x60 [ 121.434217] kernel_init_freeable+0x52f/0x6bb [ 121.447500] ? rest_init+0x1a0/0x1a0 [ 121.457489] kernel_init+0x16/0x220 [ 121.470867] ? rest_init+0x1a0/0x1a0 [ 121.480914] ret_from_fork+0x1f/0x30 [ 121.494348] ---[ end trace bb75a6ff13d6153b ]--- To reproduce: git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k job-script # job-script is attached in this email Thanks, Rong, Chen