Hi Jens and Dennis, The following warning can be triggered on for-4.21/block when running xfstests generic/475(xfs), and it is introduced by recent Dennis's patches. test disk: virtio-blk scratch: nvme-pci disk [ 979.359696] ------------[ cut here ]------------ [ 979.360800] percpu ref (blkg_release) <= 0 (0) after switching to atomic [ 979.360870] WARNING: CPU: 13 PID: 0 at lib/percpu-refcount.c:155 percpu_ref_switch_to_atomic_rcu+0x2c9/0x4a0 [ 979.363815] Modules linked in: dm_mod xfs libcrc32c iTCO_wdt iTCO_vendor_support crc32c_intel usb_storage i2c_i801 lpc_ich i2c_core mfd_core virtio_scsi nvme nvme_core qemu_fw_cfg ip_tables [ 979.366810] CPU: 13 PID: 0 Comm: swapper/13 Not tainted 4.20.0-rc6+ #542 [ 979.368017] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-2.fc27 04/01/2014 [ 979.369525] RIP: 0010:percpu_ref_switch_to_atomic_rcu+0x2c9/0x4a0 [ 979.370389] Code: 43 d8 4c 89 bd 58 ff ff ff 41 c6 45 00 f8 48 8d 78 10 e8 87 6e c8 ff 48 8b 73 e8 4c 89 fa 48 c7 c7 80 35 62 82 e8 ec ca 91 ff <0f> 0b 48 8d 43 d8 4c 8d 68 18 4c 89 ef e8 62 6e c8 ff 48 8b 43 f0 [ 979.372972] RSP: 0018:ffff888126a076b0 EFLAGS: 00010286 [ 979.373716] RAX: 0000000000000000 RBX: ffff88811d465e30 RCX: 0000000000000000 [ 979.374723] RDX: ffffed1024d40e8b RSI: 0000000000000000 RDI: ffffed1024d40eb3 [ 979.375721] RBP: ffff888126a07810 R08: dffffc0000000000 R09: fffffbfff04c46b6 [ 979.376719] R10: ffffed1023a8cbc2 R11: fffffbfff05a5dcc R12: 1ffff11024d40ed9 [ 979.377716] R13: ffffed1024d40eed R14: ffff88811d465e10 R15: 0000000000000000 [ 979.378719] FS: 0000000000000000(0000) GS:ffff888126a00000(0000) knlGS:0000000000000000 [ 979.379842] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 979.380636] CR2: 000055762ef5ce00 CR3: 000000026f078002 CR4: 0000000000760ee0 [ 979.381642] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 979.382639] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 979.383642] PKRU: 55555554 [ 979.384049] Call Trace: [ 979.384405] <IRQ> [ 979.384746] ? percpu_ref_exit+0x4c/0x4c [ 979.385310] ? lock_acquire+0x280/0x2f3 [ 979.385877] ? rcu_process_callbacks+0xaad/0xf72 [ 979.386535] ? lock_downgrade+0x338/0x338 [ 979.387128] ? lockdep_hardirqs_on+0x26b/0x278 [ 979.387780] ? trace_hardirqs_on+0x169/0x19e [ 979.388386] ? rcu_get_gp_kthreads_prio+0xc/0xc [ 979.389063] rcu_process_callbacks+0xb9f/0xf72 [ 979.389726] ? percpu_ref_exit+0x4c/0x4c [ 979.390294] ? rcu_preempt_deferred_qs+0x86/0x86 [ 979.390979] ? kvm_clock_read+0x14/0x23 [ 979.391518] ? kvm_sched_clock_read+0x5/0xd [ 979.392128] ? check_chain_key+0x150/0x1aa [ 979.392770] ? do_raw_spin_trylock+0x156/0x1a2 [ 979.393393] ? mark_held_locks+0x28/0x7f [ 979.393970] ? _raw_spin_unlock_irq+0x29/0x4c [ 979.394590] ? lockdep_hardirqs_on+0x26b/0x278 [ 979.395233] ? trace_hardirqs_on+0x169/0x19e [ 979.395854] ? __bpf_trace_preemptirq_template+0x5/0x5 [ 979.396566] ? do_raw_spin_trylock+0x1a2/0x1a2 [ 979.397204] ? cpu_load_update_active+0x168/0x1ab [ 979.397885] ? debug_show_all_locks+0x354/0x354 [ 979.398536] ? preempt_count_sub+0x14/0xc4 [ 979.399134] ? _raw_spin_unlock_irq+0x3a/0x4c [ 979.399765] ? run_timer_softirq+0x2fb/0x33e [ 979.400368] ? expire_timers+0x34f/0x34f [ 979.400956] ? timerqueue_add+0xc7/0xe1 [ 979.401500] ? match_held_lock+0x84/0x2db [ 979.402090] ? pvclock_clocksource_read+0x121/0x205 [ 979.402799] ? pvclock_read_flags+0x37/0x37 [ 979.403387] ? trace_hardirqs_off+0x169/0x19e [ 979.404023] ? rcu_pm_notify+0x64/0x64 [ 979.404571] ? kvm_clock_read+0x14/0x23 [ 979.405132] ? kvm_sched_clock_read+0x5/0xd [ 979.405737] ? check_chain_key+0x150/0x1aa [ 979.406329] ? mark_held_locks+0x28/0x7f [ 979.406903] ? __do_softirq+0x18a/0x6ad [ 979.407456] ? preempt_count_sub+0x14/0xc4 [ 979.408058] ? rcu_lockdep_current_cpu_online+0x100/0x147 [ 979.408834] ? rcu_pm_notify+0x64/0x64 [ 979.409367] ? __lock_is_held+0x2a/0x87 [ 979.409967] __do_softirq+0x360/0x6ad [ 979.410512] ? __irqentry_text_end+0x1fb69a/0x1fb69a [ 979.411223] ? ktime_get+0x1a0/0x242 [ 979.411763] ? ktime_get_real_ts64+0x275/0x275 [ 979.412388] ? _raw_spin_unlock_irqrestore+0x3d/0x6b [ 979.413091] ? lockdep_hardirqs_off+0x140/0x14a [ 979.413760] ? trace_hardirqs_off+0x169/0x19e [ 979.414387] ? nr_iowait_cpu+0xa3/0xcf [ 979.414941] ? irq_exit+0x13/0x11d [ 979.415431] ? lockdep_hardirqs_off+0x140/0x14a [ 979.416089] ? trace_hardirqs_off+0x169/0x19e [ 979.416723] ? trace_hardirqs_on_caller+0x1a6/0x1a6 [ 979.417403] ? rcu_pm_notify+0x64/0x64 [ 979.417951] ? __lock_is_held+0x2a/0x87 [ 979.418517] irq_exit+0x7e/0x11d [ 979.419008] smp_apic_timer_interrupt+0x3e1/0x432 [ 979.419683] ? smp_call_function_single_interrupt+0x3b8/0x3b8 [ 979.420492] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 979.421164] ? lockdep_hardirqs_off+0x11c/0x14a [ 979.421824] ? trace_hardirqs_off_caller+0x16f/0x1a6 [ 979.422519] ? trace_hardirqs_off+0x19e/0x19e [ 979.423150] ? trace_hardirqs_off+0x19e/0x19e [ 979.423795] ? kvm_clock_read+0x14/0x23 [ 979.424353] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 979.425054] apic_timer_interrupt+0xf/0x20 [ 979.425636] </IRQ> [ 979.425966] RIP: 0010:native_safe_halt+0x2/0x3 [ 979.426586] Code: 63 02 df f0 83 44 24 fc 00 48 89 df e8 bb 73 5f ff 48 8b 03 a8 08 74 0b 65 81 25 2d 93 1c 7e ff ff ff 7f 5b 5d 41 5c c3 fb f4 <c3> f4 c3 0f 1f 44 00 00 41 57 41 56 48 b8 00 00 00 00 00 fc ff df [ 979.429149] RSP: 0018:ffff8881073c7cf8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 [ 979.430201] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8119db2b [ 979.431195] RDX: 1ffffffff065e441 RSI: 0000000000000007 RDI: ffff8881073b4d5c [ 979.432185] RBP: 1ffff11020e78fa0 R08: dffffc0000000000 R09: 0000000000000001 [ 979.433175] R10: ffffed1024d7fc48 R11: ffffed1024d7fc47 R12: 0000000000000000 [ 979.434162] R13: dffffc0000000000 R14: 1ffff11020e78fbc R15: 0000000000000000 [ 979.435180] ? lockdep_hardirqs_on+0x26b/0x278 [ 979.435842] default_idle+0x165/0x2a0 [ 979.436361] ? __sched_text_end+0x1/0x1 [ 979.436934] ? mark_tsc_async_resets+0x25/0x25 [ 979.437549] ? trace_hardirqs_on_caller+0x1a6/0x1a6 [ 979.438277] do_idle+0x16b/0x2e9 [ 979.438765] ? arch_cpu_idle_exit+0x28/0x28 [ 979.439358] ? schedule_idle+0x3b/0x44 [ 979.439927] cpu_startup_entry+0x1d/0x1f [ 979.440478] start_secondary+0x338/0x36c [ 979.441053] ? set_cpu_sibling_map+0x8a3/0x8a3 [ 979.441742] secondary_startup_64+0xa4/0xb0 [ 979.442376] irq event stamp: 1890071 [ 979.442899] hardirqs last enabled at (1890070): [<ffffffff811bc221>] vprintk_emit+0x276/0x553 [ 979.444084] hardirqs last disabled at (1890071): [<ffffffff810045e5>] trace_hardirqs_off_thunk+0x1a/0x1c [ 979.445380] softirqs last enabled at (1890048): [<ffffffff810f0314>] irq_enter+0x4c/0x73 [ 979.446500] softirqs last disabled at (1890049): [<ffffffff810f03b9>] irq_exit+0x7e/0x11d [ 979.447618] ---[ end trace 181fb562d15b7328 ]--- [ 979.456959] XFS (sdc): Unmounting Filesystem _check_dmesg: something found in dmesg (see /var/lib/xfstests/results//generic/475.dmesg) Ran: generic/475 Failures: generic/475 Failed 1 of 1 tests Thanks, Ming
