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[46.22.16.76]) by smtp.gmail.com with ESMTPSA id y10sm651835ejq.50.2021.06.10.00.28.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 10 Jun 2021 00:28:26 -0700 (PDT) Subject: Re: Hung task in 4.9 using kvm 5.2 From: Christoph Mathys To: Luis Goncalves , "Ahmed S. Darwish" Cc: Linux RT Users References: Message-ID: <0d6485d8-62d2-0e28-fb30-b52883dc0ecf@gmail.com> Date: Thu, 10 Jun 2021 09:28:25 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org I think the "hung task" problem is caused by a combination of flags to the -blockdev argument of kvm: aio=native and cache.direct=true When I remove this two settings and just use the kvm default I'm no longer able to reproduce the problem. However, a bit later in the test, another problem occurs: Jun 09 17:23:28 hostname kernel: BUG: unable to handle kernel paging request at fffffffffffffe5a Jun 09 17:23:28 hostname kernel: IP: [] kmem_cache_alloc+0x77/0x290 Jun 09 17:23:28 hostname kernel: PGD 1e15067 Jun 09 17:23:28 hostname kernel: PUD 1e17067 Jun 09 17:23:28 hostname kernel: PMD 0 Jun 09 17:23:28 hostname kernel: Jun 09 17:23:28 hostname kernel: Oops: 0000 [#1] PREEMPT SMP Jun 09 17:23:28 hostname kernel: Modules linked in: cmac arc4 md4 nls_utf8 nft_meta nft_compat nft_chain_nat_ipv6 nf_tables_ipv6 nft_chain_nat_ipv4 nft_counter nf_tables_ipv4 nf_tables binfmt_misc veth ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 xt_comment nf_conntrack_netlink nfnetlink xfrm_user xfrm_algo xt_addrtype br_netfilter xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter overlay joydev snd_usb_audio snd_usbmidi_lib coretemp ghash_clmulni_intel aesni_intel snd_hda_codec_hdmi aes_x86_64 lrw gf128mul glue_helper ablk_helper snd_hda_codec_realtek cryptd snd_hda_codec_generic snd_hda_intel Jun 09 17:23:28 hostname kernel: snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi i915 snd_seq snd_seq_device drm_kms_helper snd_timer drm fb_sys_fops snd syscopyarea sysfillrect soundcore sysimgblt shpchp video mac_hid acpi_pad tpm_tis tpm_tis_core kvm_intel kvm irqbypass squashfs sch_fq_codel cifs fscache parport_pc ppdev lp parport ip_tables x_tables autofs4 btrfs xor raid6_pq hid_generic hid_cherry usbhid hid igb e1000e i2c_algo_bit nvme dca nvme_core ptp pps_core Jun 09 17:23:28 hostname kernel: CPU: 5 PID: 1137 Comm: RTController Tainted: G U 4.9.271-realtime-1-prove-rt182 #1 Jun 09 17:23:28 hostname kernel: Hardware name: Komax AG, Dierikon Komax-PC/KMX-Q170-24V, BIOS D05K1-1L 03/19/2018 Jun 09 17:23:28 hostname kernel: task: ffff8804fb908000 task.stack: ffffc90015fdc000 Jun 09 17:23:28 hostname kernel: RIP: 0010:[] [] kmem_cache_alloc+0x77/0x290 Jun 09 17:23:28 hostname kernel: RSP: 0018:ffffc90015fdfe40 EFLAGS: 00010286 Jun 09 17:23:28 hostname kernel: RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000368895 Jun 09 17:23:28 hostname kernel: RDX: 0000000000368885 RSI: 0000000000368885 RDI: 000000000006c190 Jun 09 17:23:28 hostname kernel: RBP: ffffc90015fdfe70 R08: ffff8804fb908000 R09: ffffc90015fdfda0 Jun 09 17:23:28 hostname kernel: R10: 0000000000000000 R11: 000000000000003d R12: ffff88087dc03900 Jun 09 17:23:28 hostname kernel: R13: ffffffff81238ff1 R14: fffffffffffffe5a R15: 00000000024000c0 Jun 09 17:23:28 hostname kernel: FS: 00007fca5bfff700(0000) GS:ffff88087e480000(0000) knlGS:0000000000000000 Jun 09 17:23:28 hostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jun 09 17:23:28 hostname kernel: CR2: fffffffffffffe5a CR3: 00000005a6c74000 CR4: 0000000000362670 Jun 09 17:23:28 hostname kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Jun 09 17:23:28 hostname kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Jun 09 17:23:28 hostname kernel: Stack: Jun 09 17:23:28 hostname kernel: ffffffff8182ec6e 0000000000000001 ffff8805a787d341 ffff8805a787f440 Jun 09 17:23:28 hostname kernel: ffffffffffffffea ffff8805a787d340 ffffc90015fdff20 ffffffff81238ff1 Jun 09 17:23:28 hostname kernel: 0000000000000320 00000000000000e9 0000000000000000 0000000000000000 Jun 09 17:23:28 hostname kernel: Call Trace: Jun 09 17:23:28 hostname kernel: [] ? rt_mutex_lock+0x5e/0x80 Jun 09 17:23:28 hostname kernel: [] SyS_epoll_ctl+0x2d1/0xcc0 Jun 09 17:23:28 hostname kernel: [] do_syscall_64+0x7b/0x160 Jun 09 17:23:28 hostname kernel: [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Jun 09 17:23:28 hostname kernel: Code: 70 08 48 39 f2 75 e7 48 83 78 10 00 4c 8b 30 0f 84 d7 00 00 00 4d 85 f6 0f 84 ce 00 00 00 49 63 44 24 20 49 8b 3c 24 48 8d 4a 10 <49> 8b 1c 06 4c 89 f0 65 48 0f c7 0f 0f 94 c0 84 c0 74 ac 49 63 Jun 09 17:23:28 hostname kernel: RIP [] kmem_cache_alloc+0x77/0x290 Jun 09 17:23:28 hostname kernel: RSP Jun 09 17:23:28 hostname kernel: CR2: fffffffffffffe5a Jun 09 17:23:28 hostname kernel: ---[ end trace 0000000000000002 ]--- Jun 09 17:23:28 hostname kernel: BUG: unable to handle kernel paging request at ffff87faa787cafd Jun 09 17:23:28 hostname kernel: IP: [] rcu_cpu_kthread+0x2e8/0x690 Jun 09 17:23:28 hostname kernel: PGD 0 Jun 09 17:23:28 hostname kernel: Jun 09 17:23:28 hostname kernel: Oops: 0000 [#2] PREEMPT SMP Jun 09 17:23:28 hostname kernel: Modules linked in: cmac arc4 md4 nls_utf8 nft_meta nft_compat nft_chain_nat_ipv6 nf_tables_ipv6 nft_chain_nat_ipv4 nft_counter nf_tables_ipv4 nf_tables binfmt_misc veth ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 xt_comment nf_conntrack_netlink nfnetlink xfrm_user xfrm_algo xt_addrtype br_netfilter xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter overlay joydev snd_usb_audio snd_usbmidi_lib coretemp ghash_clmulni_intel aesni_intel snd_hda_codec_hdmi aes_x86_64 lrw gf128mul glue_helper ablk_helper snd_hda_codec_realtek cryptd snd_hda_codec_generic snd_hda_intel Jun 09 17:23:28 hostname kernel: snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi i915 snd_seq snd_seq_device drm_kms_helper snd_timer drm fb_sys_fops snd syscopyarea sysfillrect soundcore sysimgblt shpchp video mac_hid acpi_pad tpm_tis tpm_tis_core kvm_intel kvm irqbypass squashfs sch_fq_codel cifs fscache parport_pc ppdev lp parport ip_tables x_tables autofs4 btrfs xor raid6_pq hid_generic hid_cherry usbhid hid igb e1000e i2c_algo_bit nvme dca nvme_core ptp pps_core Jun 09 17:23:28 hostname kernel: CPU: 5 PID: 55 Comm: rcuc/5 Tainted: G UD 4.9.271-realtime-1-prove-rt182 #1 Jun 09 17:23:28 hostname kernel: Hardware name: Komax AG, Dierikon Komax-PC/KMX-Q170-24V, BIOS D05K1-1L 03/19/2018 Jun 09 17:23:28 hostname kernel: task: ffff88086c3a2800 task.stack: ffffc900113c8000 Jun 09 17:23:28 hostname kernel: RIP: 0010:[] [] rcu_cpu_kthread+0x2e8/0x690 Jun 09 17:23:28 hostname kernel: RSP: 0018:ffffc900113cbdb0 EFLAGS: 00010282 Jun 09 17:23:28 hostname kernel: RAX: ffff88086c3a2800 RBX: ffffffff812371a0 RCX: 0000000000000000 Jun 09 17:23:28 hostname kernel: RDX: ffffffff810d536e RSI: 0000000000000001 RDI: ffffffff81e67360 Jun 09 17:23:28 hostname kernel: RBP: ffffc900113cbe30 R08: 0000000000000000 R09: 0000000000000000 Jun 09 17:23:28 hostname kernel: R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000005 Jun 09 17:23:28 hostname kernel: R13: ffff88086c3a2800 R14: ffff87faa787cafd R15: ffff87faa787cafd Jun 09 17:23:28 hostname kernel: FS: 0000000000000000(0000) GS:ffff88087e480000(0000) knlGS:0000000000000000 Jun 09 17:23:28 hostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jun 09 17:23:28 hostname kernel: CR2: ffff87faa787cafd CR3: 0000000572896000 CR4: 0000000000362670 Jun 09 17:23:28 hostname kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Jun 09 17:23:28 hostname kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Jun 09 17:23:28 hostname kernel: Stack: Jun 09 17:23:28 hostname kernel: ffffffff810d53c5 ffff88086c3a2800 ffff8807deff38c0 0000000a00000000 Jun 09 17:23:28 hostname kernel: ffff88087e4920bc ffff88087e4e9480 ffffffff81e67500 ffff88087e4920b4 Jun 09 17:23:28 hostname kernel: 0000000000000002 ffff88087e4e94b8 000000000000000a ffff88086c3a2800 Jun 09 17:23:28 hostname kernel: Call Trace: Jun 09 17:23:28 hostname kernel: [] ? rcu_cpu_kthread+0x2e5/0x690 Jun 09 17:23:28 hostname kernel: [] ? smpboot_register_percpu_thread_cpumask+0xf0/0xf0 Jun 09 17:23:28 hostname kernel: [] smpboot_thread_fn+0x120/0x250 Jun 09 17:23:28 hostname kernel: [] kthread+0xe0/0x100 Jun 09 17:23:28 hostname kernel: [] ? kthread_create_on_node+0x40/0x40 Jun 09 17:23:28 hostname kernel: [] ret_from_fork+0x59/0x70 Jun 09 17:23:28 hostname kernel: Code: 8b 55 00 83 e2 08 0f 85 87 00 00 00 49 8b 55 00 f7 c2 00 00 04 00 75 7b 41 8b 85 a8 04 00 00 85 c0 75 70 4d 85 f6 74 6b 4d 89 f7 <4d> 8b 36 45 31 c9 45 31 c0 49 8b 5f 08 31 d2 31 f6 b9 02 00 00 Jun 09 17:23:28 hostname kernel: RIP [] rcu_cpu_kthread+0x2e8/0x690 Jun 09 17:23:28 hostname kernel: RSP Jun 09 17:23:28 hostname kernel: CR2: ffff87faa787cafd Jun 09 17:23:28 hostname kernel: ---[ end trace 0000000000000003 ]--- Jun 09 17:23:28 hostname kernel: BUG: unable to handle kernel paging request at ffffffff81443890 Jun 09 17:23:28 hostname kernel: IP: [] queued_spin_lock_slowpath+0x149/0x190 Jun 09 17:23:28 hostname kernel: PGD 1e15067 Jun 09 17:23:28 hostname kernel: PUD 1e16063 Jun 09 17:23:28 hostname kernel: PMD 14000e1 Jun 09 17:23:28 hostname kernel: Jun 09 17:23:28 hostname kernel: Oops: 0003 [#3] PREEMPT SMP Jun 09 17:23:28 hostname kernel: Modules linked in: cmac arc4 md4 nls_utf8 nft_meta nft_compat nft_chain_nat_ipv6 nf_tables_ipv6 nft_chain_nat_ipv4 nft_counter nf_tables_ipv4 nf_tables binfmt_misc veth ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 xt_comment nf_conntrack_netlink nfnetlink xfrm_user xfrm_algo xt_addrtype br_netfilter xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter overlay joydev snd_usb_audio snd_usbmidi_lib coretemp ghash_clmulni_intel aesni_intel snd_hda_codec_hdmi aes_x86_64 lrw gf128mul glue_helper ablk_helper snd_hda_codec_realtek cryptd snd_hda_codec_generic snd_hda_intel Jun 09 17:23:28 hostname kernel: snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi i915 snd_seq snd_seq_device drm_kms_helper snd_timer drm fb_sys_fops snd syscopyarea sysfillrect soundcore sysimgblt shpchp video mac_hid acpi_pad tpm_tis tpm_tis_core kvm_intel kvm irqbypass squashfs sch_fq_codel cifs fscache parport_pc ppdev lp parport ip_tables x_tables autofs4 btrfs xor raid6_pq hid_generic hid_cherry usbhid hid igb e1000e i2c_algo_bit nvme dca nvme_core ptp pps_core Jun 09 17:23:28 hostname kernel: CPU: 5 PID: 55 Comm: rcuc/5 Tainted: G UD 4.9.271-realtime-1-prove-rt182 #1 Jun 09 17:23:28 hostname kernel: Hardware name: Komax AG, Dierikon Komax-PC/KMX-Q170-24V, BIOS D05K1-1L 03/19/2018 Jun 09 17:23:28 hostname kernel: task: ffff88086c3a2800 task.stack: ffffc900113c8000 Jun 09 17:23:28 hostname kernel: RIP: 0010:[] [] queued_spin_lock_slowpath+0x149/0x190 Jun 09 17:23:28 hostname kernel: RSP: 0018:ffffc900113cbe28 EFLAGS: 00010086 Jun 09 17:23:28 hostname kernel: RAX: ffffffff81443890 RBX: ffffc900113cbee0 RCX: ffff88087e4e9440 Jun 09 17:23:28 hostname kernel: RDX: 0000000000002040 RSI: 0000000000180000 RDI: ffffc900113cbee0 Jun 09 17:23:28 hostname kernel: RBP: ffffc900113cbe28 R08: 0000000000000000 R09: 0000000000000001 Jun 09 17:23:28 hostname kernel: R10: 0000000000000000 R11: 0000000000000000 R12: ffffc900113cbee0 Jun 09 17:23:28 hostname kernel: R13: 0000000000000286 R14: 0000000000000001 R15: 0000000000000001 Jun 09 17:23:28 hostname kernel: FS: 0000000000000000(0000) GS:ffff88087e480000(0000) knlGS:0000000000000000 Jun 09 17:23:28 hostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jun 09 17:23:28 hostname kernel: CR2: ffffffff81443890 CR3: 00000005a6d9a000 CR4: 0000000000362670 Jun 09 17:23:28 hostname kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Jun 09 17:23:28 hostname kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Jun 09 17:23:28 hostname kernel: Stack: Jun 09 17:23:28 hostname kernel: ffffc900113cbe40 ffffffff810bb72d ffffc900113cbed8 ffffc900113cbe68 Jun 09 17:23:28 hostname kernel: ffffffff81830b2d ffffffff810adc4d ffffc900113cbee0 ffff88086c3a2ff8 Jun 09 17:23:28 hostname kernel: ffffc900113cbe90 ffffffff810adc4d ffff88086c3a2800 ffff88086c3a2800 Jun 09 17:23:28 hostname kernel: Call Trace: Jun 09 17:23:28 hostname kernel: [] do_raw_spin_lock+0x9d/0xa0 Jun 09 17:23:28 hostname kernel: [] _raw_spin_lock_irqsave+0x4d/0x60 Jun 09 17:23:28 hostname kernel: [] ? complete+0x1d/0x40 Jun 09 17:23:28 hostname kernel: [] complete+0x1d/0x40 Jun 09 17:23:28 hostname kernel: [] mm_release+0x84/0xe0 Jun 09 17:23:28 hostname kernel: [] exit_mm_release+0x23/0x30 Jun 09 17:23:28 hostname kernel: [] ? rewind_stack_do_exit+0x17/0x20 Jun 09 17:23:28 hostname kernel: Code: 01 00 00 74 ef 40 30 f6 e9 ed fe ff ff c1 ea 12 83 e0 03 83 ea 01 48 c1 e0 04 48 63 d2 48 05 40 94 06 00 48 03 04 d5 20 c4 cd 81 <48> 89 08 8b 41 08 85 c0 75 09 f3 90 8b 41 08 85 c0 74 f7 48 8b Jun 09 17:23:28 hostname kernel: RIP [] queued_spin_lock_slowpath+0x149/0x190 Jun 09 17:23:28 hostname kernel: RSP Jun 09 17:23:28 hostname kernel: CR2: ffffffff81443890 Jun 09 17:23:28 hostname kernel: ---[ end trace 0000000000000004 ]--- Jun 09 17:23:28 hostname kernel: note: rcuc/5[55] exited with preempt_count 1 Jun 09 17:23:28 hostname kernel: Fixing recursive fault but reboot is needed! Jun 09 17:23:28 hostname kernel: ------------[ cut here ]------------ Jun 09 17:23:28 hostname kernel: kernel BUG at kernel/locking/rtmutex.c:1070! Jun 09 17:23:28 hostname kernel: invalid opcode: 0000 [#4] PREEMPT SMP Jun 09 17:23:28 hostname kernel: Modules linked in: cmac arc4 md4 nls_utf8 nft_meta nft_compat nft_chain_nat_ipv6 nf_tables_ipv6 nft_chain_nat_ipv4 nft_counter nf_tables_ipv4 nf_tables binfmt_misc veth ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 xt_comment nf_conntrack_netlink nfnetlink xfrm_user xfrm_algo xt_addrtype br_netfilter xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter overlay joydev snd_usb_audio snd_usbmidi_lib coretemp ghash_clmulni_intel aesni_intel snd_hda_codec_hdmi aes_x86_64 lrw gf128mul glue_helper ablk_helper snd_hda_codec_realtek cryptd snd_hda_codec_generic snd_hda_intel Jun 09 17:23:28 hostname kernel: snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi i915 snd_seq snd_seq_device drm_kms_helper snd_timer drm fb_sys_fops snd syscopyarea sysfillrect soundcore sysimgblt shpchp video mac_hid acpi_pad tpm_tis tpm_tis_core kvm_intel kvm irqbypass squashfs sch_fq_codel cifs fscache parport_pc ppdev lp parport ip_tables x_tables autofs4 btrfs xor raid6_pq hid_generic hid_cherry usbhid hid igb e1000e i2c_algo_bit nvme dca nvme_core ptp pps_core Jun 09 17:23:28 hostname kernel: CPU: 5 PID: 55 Comm: rcuc/5 Tainted: G UD 4.9.271-realtime-1-prove-rt182 #1 Jun 09 17:23:28 hostname kernel: Hardware name: Komax AG, Dierikon Komax-PC/KMX-Q170-24V, BIOS D05K1-1L 03/19/2018 Jun 09 17:23:28 hostname kernel: task: ffff88086c3a2800 task.stack: ffffc900113c8000 Jun 09 17:23:28 hostname kernel: RIP: 0010:[] [] rt_spin_lock_slowlock+0x325/0x350 Jun 09 17:23:28 hostname kernel: RSP: 0018:ffffc900113cbdd8 EFLAGS: 00010046 Jun 09 17:23:28 hostname kernel: RAX: ffff88086c3a2800 RBX: ffff88086c3a2ff8 RCX: 0000000000000001 Jun 09 17:23:28 hostname kernel: RDX: 0000000000000000 RSI: ffff88086c3a2800 RDI: ffff88086c3a2ff8 Jun 09 17:23:28 hostname kernel: RBP: ffffc900113cbe90 R08: 0000000000000000 R09: 0000000000000001 Jun 09 17:23:28 hostname kernel: R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000282 Jun 09 17:23:28 hostname kernel: R13: ffffc900113cbdf8 R14: ffff88086c3a2800 R15: 0000000000000000 Jun 09 17:23:28 hostname kernel: FS: 0000000000000000(0000) GS:ffff88087e480000(0000) knlGS:0000000000000000 Jun 09 17:23:28 hostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jun 09 17:23:28 hostname kernel: CR2: ffffffff81443890 CR3: 00000004e72d0000 CR4: 0000000000362670 Jun 09 17:23:28 hostname kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Jun 09 17:23:28 hostname kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Jun 09 17:23:28 hostname kernel: Stack: Jun 09 17:23:28 hostname kernel: ffff88086c3a2800 0000000000000282 ffff8808013a39f0 0000000000000282 Jun 09 17:23:28 hostname kernel: ffffc900113cbdf8 1111111111111111 1111111111111111 ffffc900113cbe10 Jun 09 17:23:28 hostname kernel: 1111111111111111 1111111111111111 0000000000000000 1111111111111111 Jun 09 17:23:28 hostname kernel: Call Trace: Jun 09 17:23:28 hostname kernel: [] rt_spin_lock+0x23/0x50 Jun 09 17:23:28 hostname kernel: [] exit_files+0x2c/0x50 Jun 09 17:23:28 hostname kernel: [] do_exit+0x2d4/0xb10 Jun 09 17:23:28 hostname kernel: [] rewind_stack_do_exit+0x17/0x20 Jun 09 17:23:28 hostname kernel: Code: c0 0f 85 f9 fe ff ff 48 c7 c2 68 1c c2 81 be 80 03 00 00 48 c7 c7 60 17 c2 81 c6 05 7e ab 71 00 01 e8 50 6c 88 ff e9 d5 fe ff ff <0f> 0b 0f 0b 48 8b 43 40 48 3b 58 38 0f 85 31 ff ff ff 4c 39 e8 Jun 09 17:23:28 hostname kernel: RIP [] rt_spin_lock_slowlock+0x325/0x350 Jun 09 17:23:28 hostname kernel: RSP Jun 09 17:23:29 hostname kernel: ---[ end trace 0000000000000005 ]--- Jun 09 17:23:29 hostname kernel: note: rcuc/5[55] exited with preempt_count 1 Jun 09 17:23:29 hostname kernel: Fixing recursive fault but reboot is needed!