Hi Paolo, I applied this to master.today, flipped udev back to bfq and took it for a spin. Unfortunately, box fairly quickly went boom under load. [ 454.739975] ------------[ cut here ]------------ [ 454.739979] list_add corruption. prev->next should be next (000000005f99a42a), but was (null). (prev=00000000fc569ec9). [ 454.739989] WARNING: CPU: 3 PID: 0 at lib/list_debug.c:28 __list_add_valid+0x6a/0x70 [ 454.739990] Modules linked in: fuse(E) ebtable_filter(E) ebtables(E) af_packet(E) bridge(E) stp(E) llc(E) iscsi_ibft(E) iscsi_boot_sysfs(E) nf_conntrack_ipv6(E) nf_defrag_ipv6(E) ipt_REJECT(E) xt_tcpudp(E) iptable_filter(E) ip6table_mangle(E) nf_conntrack_netbios_ns(E) nf_conntrack_broadcast(E) nf_conntrack_ipv4(E) nf_defrag_ipv4(E) ip_tables(E) xt_conntrack(E) nf_conntrack(E) ip6table_filter(E) ip6_tables(E) x_tables(E) nls_iso8859_1(E) nls_cp437(E) intel_rapl(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) snd_hda_codec_hdmi(E) coretemp(E) snd_hda_codec_realtek(E) snd_hda_codec_generic(E) kvm_intel(E) kvm(E) snd_hda_intel(E) snd_hda_codec(E) snd_hwdep(E) snd_hda_core(E) snd_pcm(E) irqbypass(E) snd_timer(E) joydev(E) crct10dif_pclmul(E) snd(E) r8169(E) crc32_pclmul(E) mii(E) mei_me(E) soundcore(E) [ 454.740011] crc32c_intel(E) iTCO_wdt(E) ghash_clmulni_intel(E) iTCO_vendor_support(E) pcbc(E) mei(E) lpc_ich(E) aesni_intel(E) i2c_i801(E) mfd_core(E) aes_x86_64(E) shpchp(E) intel_smartconnect(E) crypto_simd(E) glue_helper(E) cryptd(E) pcspkr(E) fan(E) thermal(E) nfsd(E) auth_rpcgss(E) nfs_acl(E) lockd(E) grace(E) sunrpc(E) sr_mod(E) cdrom(E) hid_logitech_hidpp(E) hid_logitech_dj(E) uas(E) usb_storage(E) hid_generic(E) usbhid(E) nouveau(E) wmi(E) i2c_algo_bit(E) drm_kms_helper(E) syscopyarea(E) sysfillrect(E) sysimgblt(E) fb_sys_fops(E) ahci(E) xhci_pci(E) ttm(E) libahci(E) ehci_pci(E) xhci_hcd(E) ehci_hcd(E) libata(E) drm(E) usbcore(E) video(E) button(E) sd_mod(E) vfat(E) fat(E) virtio_blk(E) virtio_mmio(E) virtio_pci(E) virtio_ring(E) virtio(E) ext4(E) crc16(E) mbcache(E) jbd2(E) loop(E) sg(E) [ 454.740038] dm_multipath(E) dm_mod(E) scsi_dh_rdac(E) scsi_dh_emc(E) scsi_dh_alua(E) scsi_mod(E) efivarfs(E) autofs4(E) [ 454.740043] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G E 4.15.0.ge237f98-master #605 [ 454.740044] Hardware name: MEDION MS-7848/MS-7848, BIOS M7848W08.20C 09/23/2013 [ 454.740046] RIP: 0010:__list_add_valid+0x6a/0x70 [ 454.740047] RSP: 0018:ffff88041ecc3ca8 EFLAGS: 00010096 [ 454.740048] RAX: 0000000000000075 RBX: ffff8803f33fa8c0 RCX: 0000000000000006 [ 454.740049] RDX: 0000000000000000 RSI: 0000000000000082 RDI: ffff88041ecd5570 [ 454.740050] RBP: ffff8803f596d7e0 R08: 0000000000000000 R09: 0000000000000368 [ 454.740051] R10: 0000000000000000 R11: ffff88041ecc3a30 R12: ffff8803eb1c8828 [ 454.740052] R13: ffff8803f33fa940 R14: ffff8803f5852600 R15: ffff8803f596d810 [ 454.740053] FS: 0000000000000000(0000) GS:ffff88041ecc0000(0000) knlGS:0000000000000000 [ 454.740054] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 454.740055] CR2: 00000000014d9788 CR3: 0000000001e0a006 CR4: 00000000001606e0 [ 454.740056] Call Trace: [ 454.740058] <IRQ> [ 454.740062] blk_flush_complete_seq+0x2b1/0x370 [ 454.740065] flush_end_io+0x18c/0x280 [ 454.740074] scsi_end_request+0x95/0x1e0 [scsi_mod] [ 454.740079] scsi_io_completion+0xbb/0x5d0 [scsi_mod] [ 454.740082] __blk_mq_complete_request+0xb7/0x180 [ 454.740084] blk_mq_complete_request+0x50/0x90 [ 454.740087] ? scsi_vpd_tpg_id+0x90/0x90 [scsi_mod] [ 454.740095] ata_scsi_qc_complete+0x1d8/0x470 [libata] [ 454.740100] ata_qc_complete_multiple+0x87/0xd0 [libata] [ 454.740103] ahci_handle_port_interrupt+0xd4/0x4e0 [libahci] [ 454.740105] ahci_handle_port_intr+0x6f/0xb0 [libahci] [ 454.740107] ahci_single_level_irq_intr+0x3b/0x60 [libahci] [ 454.740110] __handle_irq_event_percpu+0x40/0x1a0 [ 454.740112] handle_irq_event_percpu+0x20/0x50 [ 454.740114] handle_irq_event+0x36/0x60 [ 454.740116] handle_edge_irq+0x90/0x190 [ 454.740118] handle_irq+0x1c/0x30 [ 454.740120] do_IRQ+0x43/0xd0 [ 454.740122] common_interrupt+0xa2/0xa2 [ 454.740123] </IRQ> [ 454.740125] RIP: 0010:cpuidle_enter_state+0xec/0x250 [ 454.740126] RSP: 0018:ffff880187febec0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdd [ 454.740127] RAX: ffff88041ece0040 RBX: ffff88041ece77e8 RCX: 000000000000001f [ 454.740128] RDX: 0000000000000000 RSI: fffffffd9cb7bc38 RDI: 0000000000000000 [ 454.740129] RBP: 0000000000000005 R08: 0000000000000006 R09: 000000000000024f [ 454.740130] R10: 0000000000000205 R11: 0000000000000018 R12: 0000000000000003 [ 454.740131] R13: 00000069e09a3c87 R14: 0000000000000003 R15: 00000069e09d450c [ 454.740134] do_idle+0x16a/0x1d0 [ 454.740136] cpu_startup_entry+0x19/0x20 [ 454.740138] start_secondary+0x14e/0x190 [ 454.740140] secondary_startup_64+0xa5/0xb0 [ 454.740141] Code: fe 31 c0 48 c7 c7 a0 61 bf 81 e8 12 f7 d8 ff 0f ff 31 c0 c3 48 89 d1 48 c7 c7 50 61 bf 81 48 89 f2 48 89 c6 31 c0 e8 f6 f6 d8 ff <0f> ff 31 c0 c3 90 48 8b 07 48 b9 00 01 00 00 00 00 ad de 48 8b [ 454.740159] ---[ end trace c2b6ab81731e93a0 ]--- [ 454.740278] ------------[ cut here ]------------ [ 454.740281] list_del corruption. prev->next should be 0000000056dbdea8, but was 00000000577efd13 [ 454.740286] WARNING: CPU: 3 PID: 0 at lib/list_debug.c:53 __list_del_entry_valid+0x7c/0xa0 [ 454.740287] Modules linked in: fuse(E) ebtable_filter(E) ebtables(E) af_packet(E) bridge(E) stp(E) llc(E) iscsi_ibft(E) iscsi_boot_sysfs(E) nf_conntrack_ipv6(E) nf_defrag_ipv6(E) ipt_REJECT(E) xt_tcpudp(E) iptable_filter(E) ip6table_mangle(E) nf_conntrack_netbios_ns(E) nf_conntrack_broadcast(E) nf_conntrack_ipv4(E) nf_defrag_ipv4(E) ip_tables(E) xt_conntrack(E) nf_conntrack(E) ip6table_filter(E) ip6_tables(E) x_tables(E) nls_iso8859_1(E) nls_cp437(E) intel_rapl(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) snd_hda_codec_hdmi(E) coretemp(E) snd_hda_codec_realtek(E) snd_hda_codec_generic(E) kvm_intel(E) kvm(E) snd_hda_intel(E) snd_hda_codec(E) snd_hwdep(E) snd_hda_core(E) snd_pcm(E) irqbypass(E) snd_timer(E) joydev(E) crct10dif_pclmul(E) snd(E) r8169(E) crc32_pclmul(E) mii(E) mei_me(E) soundcore(E) [ 454.740302] crc32c_intel(E) iTCO_wdt(E) ghash_clmulni_intel(E) iTCO_vendor_support(E) pcbc(E) mei(E) lpc_ich(E) aesni_intel(E) i2c_i801(E) mfd_core(E) aes_x86_64(E) shpchp(E) intel_smartconnect(E) crypto_simd(E) glue_helper(E) cryptd(E) pcspkr(E) fan(E) thermal(E) nfsd(E) auth_rpcgss(E) nfs_acl(E) lockd(E) grace(E) sunrpc(E) sr_mod(E) cdrom(E) hid_logitech_hidpp(E) hid_logitech_dj(E) uas(E) usb_storage(E) hid_generic(E) usbhid(E) nouveau(E) wmi(E) i2c_algo_bit(E) drm_kms_helper(E) syscopyarea(E) sysfillrect(E) sysimgblt(E) fb_sys_fops(E) ahci(E) xhci_pci(E) ttm(E) libahci(E) ehci_pci(E) xhci_hcd(E) ehci_hcd(E) libata(E) drm(E) usbcore(E) video(E) button(E) sd_mod(E) vfat(E) fat(E) virtio_blk(E) virtio_mmio(E) virtio_pci(E) virtio_ring(E) virtio(E) ext4(E) crc16(E) mbcache(E) jbd2(E) loop(E) sg(E) [ 454.740321] dm_multipath(E) dm_mod(E) scsi_dh_rdac(E) scsi_dh_emc(E) scsi_dh_alua(E) scsi_mod(E) efivarfs(E) autofs4(E) [ 454.740324] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G W E 4.15.0.ge237f98-master #605 [ 454.740325] Hardware name: MEDION MS-7848/MS-7848, BIOS M7848W08.20C 09/23/2013 [ 454.740327] RIP: 0010:__list_del_entry_valid+0x7c/0xa0 [ 454.740328] RSP: 0018:ffff88041ecc3cb8 EFLAGS: 00010096 [ 454.740329] RAX: 0000000000000054 RBX: ffff8803f33fa8c0 RCX: 0000000000000006 [ 454.740330] RDX: 0000000000000000 RSI: 0000000000000082 RDI: ffff88041ecd5570 [ 454.740331] RBP: ffff8803f596d7e0 R08: 0000000000000101 R09: 000000000000039d [ 454.740332] R10: 0000000000000000 R11: ffff88041ecc3a40 R12: ffff8803eb1c8828 [ 454.740333] R13: ffff8803f596d7f0 R14: 0000000000000000 R15: ffff8803f33fa940 [ 454.740334] FS: 0000000000000000(0000) GS:ffff88041ecc0000(0000) knlGS:0000000000000000 [ 454.740335] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 454.740336] CR2: 00000000014d9788 CR3: 0000000001e0a006 CR4: 00000000001606e0 [ 454.740337] Call Trace: [ 454.740338] <IRQ> [ 454.740340] blk_flush_complete_seq+0x16e/0x370 [ 454.740343] mq_flush_data_end_io+0xb0/0x110 [ 454.740348] scsi_end_request+0x95/0x1e0 [scsi_mod] [ 454.740352] scsi_io_completion+0x10b/0x5d0 [scsi_mod] [ 454.740354] __blk_mq_complete_request+0xb7/0x180 [ 454.740355] blk_mq_complete_request+0x50/0x90 [ 454.740359] ? scsi_vpd_tpg_id+0x90/0x90 [scsi_mod] [ 454.740364] ata_scsi_qc_complete+0x1d8/0x470 [libata] [ 454.740368] ata_qc_complete_multiple+0x87/0xd0 [libata] [ 454.740371] ahci_handle_port_interrupt+0xd4/0x4e0 [libahci] [ 454.740373] ahci_handle_port_intr+0x6f/0xb0 [libahci] [ 454.740374] ahci_single_level_irq_intr+0x3b/0x60 [libahci] [ 454.740377] __handle_irq_event_percpu+0x40/0x1a0 [ 454.740379] handle_irq_event_percpu+0x20/0x50 [ 454.740380] handle_irq_event+0x36/0x60 [ 454.740382] handle_edge_irq+0x90/0x190 [ 454.740383] handle_irq+0x1c/0x30 [ 454.740385] do_IRQ+0x43/0xd0 [ 454.740386] common_interrupt+0xa2/0xa2 [ 454.740387] </IRQ> [ 454.740389] RIP: 0010:cpuidle_enter_state+0xec/0x250 [ 454.740389] RSP: 0018:ffff880187febec0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdd [ 454.740391] RAX: ffff88041ece0040 RBX: ffff88041ece77e8 RCX: 000000000000001f [ 454.740392] RDX: 0000000000000000 RSI: fffffffd9cb7bc38 RDI: 0000000000000000 [ 454.740393] RBP: 0000000000000005 R08: 0000000000000006 R09: 000000000000024f [ 454.740393] R10: 0000000000000205 R11: 0000000000000018 R12: 0000000000000003 [ 454.740394] R13: 00000069e0a06158 R14: 0000000000000003 R15: 00000069e0a1e8c6 [ 454.740397] do_idle+0x16a/0x1d0 [ 454.740399] cpu_startup_entry+0x19/0x20 [ 454.740400] start_secondary+0x14e/0x190 [ 454.740402] secondary_startup_64+0xa5/0xb0 [ 454.740403] Code: ff 31 c0 c3 48 89 fe 31 c0 48 c7 c7 80 62 bf 81 e8 8a f6 d8 ff 0f ff 31 c0 c3 48 89 fe 31 c0 48 c7 c7 40 62 bf 81 e8 74 f6 d8 ff <0f> ff 31 c0 c3 48 89 fe 31 c0 48 c7 c7 08 62 bf 81 e8 5e f6 d8 [ 454.740421] ---[ end trace c2b6ab81731e93a1 ]--- [ 454.740429] BUG: unable to handle kernel NULL pointer dereference at (null) [ 454.740980] IP: __list_del_entry_valid+0x25/0xa0 [ 454.741509] PGD 0 P4D 0 [ 454.742026] Oops: 0000 [#1] SMP PTI [ 454.742525] Dumping ftrace buffer: [ 454.743040] (ftrace buffer empty) [ 454.743529] Modules linked in: fuse(E) ebtable_filter(E) ebtables(E) af_packet(E) bridge(E) stp(E) llc(E) iscsi_ibft(E) iscsi_boot_sysfs(E) nf_conntrack_ipv6(E) nf_defrag_ipv6(E) ipt_REJECT(E) xt_tcpudp(E) iptable_filter(E) ip6table_mangle(E) nf_conntrack_netbios_ns(E) nf_conntrack_broadcast(E) nf_conntrack_ipv4(E) nf_defrag_ipv4(E) ip_tables(E) xt_conntrack(E) nf_conntrack(E) ip6table_filter(E) ip6_tables(E) x_tables(E) nls_iso8859_1(E) nls_cp437(E) intel_rapl(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) snd_hda_codec_hdmi(E) coretemp(E) snd_hda_codec_realtek(E) snd_hda_codec_generic(E) kvm_intel(E) kvm(E) snd_hda_intel(E) snd_hda_codec(E) snd_hwdep(E) snd_hda_core(E) snd_pcm(E) irqbypass(E) snd_timer(E) joydev(E) crct10dif_pclmul(E) snd(E) r8169(E) crc32_pclmul(E) mii(E) mei_me(E) soundcore(E) [ 454.745917] crc32c_intel(E) iTCO_wdt(E) ghash_clmulni_intel(E) iTCO_vendor_support(E) pcbc(E) mei(E) lpc_ich(E) aesni_intel(E) i2c_i801(E) mfd_core(E) aes_x86_64(E) shpchp(E) intel_smartconnect(E) crypto_simd(E) glue_helper(E) cryptd(E) pcspkr(E) fan(E) thermal(E) nfsd(E) auth_rpcgss(E) nfs_acl(E) lockd(E) grace(E) sunrpc(E) sr_mod(E) cdrom(E) hid_logitech_hidpp(E) hid_logitech_dj(E) uas(E) usb_storage(E) hid_generic(E) usbhid(E) nouveau(E) wmi(E) i2c_algo_bit(E) drm_kms_helper(E) syscopyarea(E) sysfillrect(E) sysimgblt(E) fb_sys_fops(E) ahci(E) xhci_pci(E) ttm(E) libahci(E) ehci_pci(E) xhci_hcd(E) ehci_hcd(E) libata(E) drm(E) usbcore(E) video(E) button(E) sd_mod(E) vfat(E) fat(E) virtio_blk(E) virtio_mmio(E) virtio_pci(E) virtio_ring(E) virtio(E) ext4(E) crc16(E) mbcache(E) jbd2(E) loop(E) sg(E) [ 454.748901] dm_multipath(E) dm_mod(E) scsi_dh_rdac(E) scsi_dh_emc(E) scsi_dh_alua(E) scsi_mod(E) efivarfs(E) autofs4(E) [ 454.749679] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G W E 4.15.0.ge237f98-master #605 [ 454.750472] Hardware name: MEDION MS-7848/MS-7848, BIOS M7848W08.20C 09/23/2013 [ 454.751273] RIP: 0010:__list_del_entry_valid+0x25/0xa0 [ 454.752057] RSP: 0018:ffff88041ecc3cb8 EFLAGS: 00010007 [ 454.752842] RAX: 0000000000000000 RBX: ffff8803f5852580 RCX: dead000000000200 [ 454.753633] RDX: 0000000000000000 RSI: ffff8803f596d7e0 RDI: ffff8803f5852600 [ 454.754427] RBP: ffff8803f596d7e0 R08: 0000000000000004 R09: 0000000000000000 [ 454.755220] R10: ffff8803f71583d0 R11: 0000000000001000 R12: ffff8803eb1c8828 [ 454.756010] R13: ffff8803f596d800 R14: 0000000000000000 R15: ffff8803f5852600 [ 454.756798] FS: 0000000000000000(0000) GS:ffff88041ecc0000(0000) knlGS:0000000000000000 [ 454.757591] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 454.758383] CR2: 0000000000000000 CR3: 0000000001e0a006 CR4: 00000000001606e0 [ 454.759194] Call Trace: [ 454.760012] <IRQ> [ 454.760802] blk_flush_complete_seq+0x16e/0x370 [ 454.761636] mq_flush_data_end_io+0xb0/0x110 [ 454.762488] scsi_end_request+0x95/0x1e0 [scsi_mod] [ 454.763295] scsi_io_completion+0x10b/0x5d0 [scsi_mod] [ 454.764099] __blk_mq_complete_request+0xb7/0x180 [ 454.764906] blk_mq_complete_request+0x50/0x90 [ 454.765715] ? scsi_vpd_tpg_id+0x90/0x90 [scsi_mod] [ 454.766528] ata_scsi_qc_complete+0x1d8/0x470 [libata] [ 454.767357] ata_qc_complete_multiple+0x87/0xd0 [libata] [ 454.768187] ahci_handle_port_interrupt+0xd4/0x4e0 [libahci] [ 454.769001] ahci_handle_port_intr+0x6f/0xb0 [libahci] [ 454.769812] ahci_single_level_irq_intr+0x3b/0x60 [libahci] [ 454.770625] __handle_irq_event_percpu+0x40/0x1a0 [ 454.771437] handle_irq_event_percpu+0x20/0x50 [ 454.772248] handle_irq_event+0x36/0x60 [ 454.773053] handle_edge_irq+0x90/0x190 [ 454.773857] handle_irq+0x1c/0x30 [ 454.774660] do_IRQ+0x43/0xd0 [ 454.775460] common_interrupt+0xa2/0xa2 [ 454.776283] </IRQ> [ 454.777075] RIP: 0010:cpuidle_enter_state+0xec/0x250 [ 454.777870] RSP: 0018:ffff880187febec0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdd [ 454.778678] RAX: ffff88041ece0040 RBX: ffff88041ece77e8 RCX: 000000000000001f [ 454.779487] RDX: 0000000000000000 RSI: fffffffd9cb7bc38 RDI: 0000000000000000 [ 454.780299] RBP: 0000000000000005 R08: 0000000000000006 R09: 000000000000024f [ 454.781110] R10: 0000000000000205 R11: 0000000000000018 R12: 0000000000000003 [ 454.781919] R13: 00000069e0a06158 R14: 0000000000000003 R15: 00000069e0a1e8c6 [ 454.782729] do_idle+0x16a/0x1d0 [ 454.783533] cpu_startup_entry+0x19/0x20 [ 454.784339] start_secondary+0x14e/0x190 [ 454.785146] secondary_startup_64+0xa5/0xb0 [ 454.785954] Code: 0f ff 31 c0 c3 90 48 8b 07 48 b9 00 01 00 00 00 00 ad de 48 8b 57 08 48 39 c8 74 26 48 b9 00 02 00 00 00 00 ad de 48 39 ca 74 5c <48> 8b 12 48 39 d7 75 3e 48 8b 50 08 48 39 d7 75 1f b8 01 00 00 [ 454.786836] RIP: __list_del_entry_valid+0x25/0xa0 RSP: ffff88041ecc3cb8 [ 454.787704] CR2: 0000000000000000