Greetings, 0day kernel testing robot got the below dmesg and the first bad commit is https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2018.10.09a commit 8cb682da6b49f65c3acf4255d045430cec116c52 Author: Paul E. McKenney AuthorDate: Fri Sep 21 18:08:09 2018 -0700 Commit: Paul E. McKenney CommitDate: Wed Oct 3 17:36:12 2018 -0700 rcu: Affinity forward-progress test to avoid housekeeping CPUs This commit affinities the forward-progress tests to avoid hogging a housekeeping CPU on the theory that the offloaded callbacks will be running on those housekeeping CPUs. Signed-off-by: Paul E. McKenney 61fe6c84c4 MAINTAINERS: Update from @linux.vnet.ibm.com to @linux.ibm.com 8cb682da6b rcu: Affinity forward-progress test to avoid housekeeping CPUs +------------------------------------------+------------+------------+ | | 61fe6c84c4 | 8cb682da6b | +------------------------------------------+------------+------------+ | boot_successes | 37 | 0 | | boot_failures | 0 | 13 | | BUG:unable_to_handle_kernel | 0 | 13 | | Oops:#[##] | 0 | 13 | | EIP:__bitmap_weight | 0 | 13 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 13 | +------------------------------------------+------------+------------+ [ 1.414107] rcu-torture: torture_stutter task started [ 1.415593] Kprobe smoke test: started [ 1.487589] Kprobe smoke test: passed successfully [ 1.488532] Key type blacklist registered [ 1.492230] rcu-torture: rcu_torture_fwd_progress task started [ 1.493190] BUG: unable to handle kernel NULL pointer dereference at 00000000 [ 1.494373] *pde = 00000000 [ 1.494857] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC PTI [ 1.495277] CPU: 0 PID: 47 Comm: rcu_torture_fwd Tainted: G T 4.19.0-rc1-00167-g8cb682d #2 [ 1.495277] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 1.495277] EIP: __bitmap_weight+0x44/0x61 [ 1.495277] Code: 90 01 c3 83 c1 01 39 f1 75 ef f6 c2 1f 0f 95 c0 0f b6 c8 83 04 8d 7c 57 13 48 01 84 c0 74 15 f7 da 89 d1 b8 ff ff ff ff d3 e8 <23> 04 b7 f3 0f b8 c0 90 01 c3 89 d8 5b 5e 5f 5d c3 85 d2 0f 95 c0 [ 1.495277] EAX: 00000001 EBX: 00000000 ECX: ffffffff EDX: ffffffff [ 1.495277] ESI: 00000000 EDI: 00000000 EBP: 4df25ef0 ESP: 4df25ee4 [ 1.495277] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00210a03 [ 1.495277] CR0: 80050033 CR2: 00000000 CR3: 0853e000 CR4: 000406d0 [ 1.495277] Call Trace: [ 1.495277] ? rcu_busted_torture_deferred_free+0xf/0xf [ 1.495277] ? rcu_bind_current_to_nocb+0x1d/0xaa [ 1.495277] ? rcu_busted_torture_deferred_free+0xf/0xf [ 1.495277] ? rcu_torture_fwd_prog+0x3a/0x7d5 [ 1.495277] ? __schedule+0x3dc/0x119e [ 1.495277] ? do_raw_spin_unlock+0xe0/0x14f [ 1.495277] ? __kthread_parkme+0x7e/0xe8 [ 1.495277] ? __kthread_parkme+0xcf/0xe8 [ 1.495277] ? rcu_busted_torture_deferred_free+0xf/0xf [ 1.495277] ? kthread+0x190/0x192 [ 1.495277] ? rcu_busted_torture_deferred_free+0xf/0xf [ 1.495277] ? __kthread_cancel_work+0x8a/0x8a [ 1.495277] ? ret_from_fork+0x2e/0x38 [ 1.495277] Modules linked in: [ 1.495277] CR2: 0000000000000000 [ 1.495277] ---[ end trace d71c97358a9de1b6 ]--- [ 1.495277] EIP: __bitmap_weight+0x44/0x61 # HH:MM RESULT GOOD BAD GOOD_BUT_DIRTY DIRTY_NOT_BAD git bisect start 6d1a2e5e66859bda816e5f5cf4a189768a512f15 5b394b2ddf0347bef56e50c69a58773c94343ff3 -- git bisect bad 6a0dd7b5ab9dae0fcbd5029a524893464813924d # 10:01 B 0 9 24 0 Merge 'linux-review/Oleksij-Rempel/mmc-add-new-Alcor-Micro-Cardreader-driver/20181014-230322' into devel-catchup-201810150742 git bisect bad 84176ccf06fdda3b89a5ca82349c36ef8ad392ff # 10:19 B 0 9 24 0 Merge 'arm-platforms/irq/generic_handle_domain_irq' into devel-catchup-201810150742 git bisect bad b18b42355739752c2530509d535b89aff1fd1c0e # 10:30 B 0 8 23 0 Merge 'linux-review/David-Howells/rxrpc-use-correct-kvec-num-when-sending-BUSY-response-packet/20181015-050347' into devel-catchup-201810150742 git bisect bad d2e181dfcb0e6484a981fc80dd0330d4d27d5e56 # 10:47 B 0 4 19 0 Merge 'linux-review/Heiner-Kallweit/r8169-remove-unneeded-call-to-netif_stop_queue-in-rtl8169_net_suspend/20181015-062947' into devel-catchup-201810150742 git bisect bad ca1a236af592d646dc1514e385f0e4808b67d75a # 11:15 B 0 11 26 0 Merge 'rcu/dev.2018.10.09a' into devel-catchup-201810150742 git bisect good a0ca9aa6219089fdf00601cbda0fe64a0efe165c # 11:43 G 11 0 0 0 0day base guard for 'devel-catchup-201810150742' git bisect good 5998a75adbf4f85e63b06fa7723633cc84d7129b # 12:14 G 11 0 0 0 rcu: Switch last accelerate/advance to rcu_data structure git bisect good b59a9b5bf95e3541e6fe7cf0c2bef18850a40f94 # 12:53 G 11 0 0 0 rcutorture: Import a copy of nolibc git bisect bad 9dc4ef685b2750095261b6b3106313be39caad95 # 13:10 B 0 8 23 0 rcutorture: Print time since GP end upon forward-progress failure git bisect bad 2022fbc3c7b192bbbf6419d5a43c8f635c727379 # 13:38 B 0 6 21 0 doc: rcu: Better clarify the rcu_segcblist ->len field git bisect bad 676b3a727b3ebc267a0707f4c0b7bb9ca0f8f2ee # 14:05 B 0 8 23 0 rcu: Remove unused rcu_state externs git bisect good 61fe6c84c4c0b8755ec8b129977e8cdeb8960087 # 15:01 G 10 0 0 0 MAINTAINERS: Update from @linux.vnet.ibm.com to @linux.ibm.com git bisect bad 07a525319f3988ae2c28b131316522df183892de # 15:46 B 0 1 16 0 doc: Clarify RCU data-structure comment about rcu_tree fanout git bisect bad 8cb682da6b49f65c3acf4255d045430cec116c52 # 16:23 B 0 11 26 0 rcu: Affinity forward-progress test to avoid housekeeping CPUs # first bad commit: [8cb682da6b49f65c3acf4255d045430cec116c52] rcu: Affinity forward-progress test to avoid housekeeping CPUs git bisect good 61fe6c84c4c0b8755ec8b129977e8cdeb8960087 # 16:32 G 31 0 0 0 MAINTAINERS: Update from @linux.vnet.ibm.com to @linux.ibm.com # extra tests with debug options git bisect bad 8cb682da6b49f65c3acf4255d045430cec116c52 # 16:58 B 0 11 26 0 rcu: Affinity forward-progress test to avoid housekeeping CPUs # extra tests on HEAD of linux-devel/devel-catchup-201810150742 git bisect bad 6d1a2e5e66859bda816e5f5cf4a189768a512f15 # 16:58 B 0 19 37 0 0day head guard for 'devel-catchup-201810150742' --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/lkp Intel Corporation