Hi there, I have recently bought an Intel NUC6i3SYB. That's essentially a small form-factor x86_64 PC. That device runs Linux Mint. Unfortunately I see frequent kernel oopses within the ext4 subsystem and consequently loss of data, corrupted files and complete system crashes. Here's a recent call trace: [ 796.429566] systemd[1]: apt-daily.timer: Adding 4h 1min 3.723928s random time. [ 3405.666456] general protection fault: 0000 [#1] SMP [ 3405.666519] Modules linked in: rfcomm bnep binfmt_misc snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic arc4 snd_soc_skl snd_soc_skl_ipc snd_hda_ext_core iwlmvm snd_soc_sst_ipc snd_soc_sst_dsp snd_soc_core mac80211 btusb snd_compress btrtl ac97_bus snd_pcm_dmaengine dw_dmac_core snd_hda_intel snd_hda_codec snd_hda_core 8250_dw snd_hwdep intel_rapl snd_pcm x86_pkg_temp_thermal intel_powerclamp coretemp iwlwifi snd_seq_midi snd_seq_midi_event kvm_intel snd_rawmidi hci_uart btbcm btqca snd_seq cfg80211 snd_seq_device kvm btintel bluetooth snd_timer irqbypass ir_sharp_decoder ir_rc5_decoder snd ir_lirc_codec ir_jvc_decoder ir_xmp_decoder lirc_dev ir_mce_kbd_decoder ir_sanyo_decoder ir_rc6_decoder ir_sony_decoder ir_nec_decoder rc_rc6_mce soundcore ite_cir intel_lpss_acpi mei_me rc_core [ 3405.667326] idma64 virt_dma shpchp intel_lpss_pci intel_lpss mei acpi_pad acpi_als kfifo_buf industrialio mac_hid parport_pc ppdev lp parport autofs4 btrfs xor raid6_pq jitterentropy_rng drbg ansi_cprng dm_crypt algif_skcipher af_alg dm_mirror dm_region_hash dm_log crct10dif_pclmul crc32_pclmul i915_bpo intel_ips i2c_algo_bit drm_kms_helper aesni_intel syscopyarea sysfillrect aes_x86_64 lrw gf128mul glue_helper sysimgblt ablk_helper e1000e fb_sys_fops sdhci_pci cryptd ahci ptp i2c_hid drm pps_core libahci sdhci pinctrl_sunrisepoint video hid pinctrl_intel fjes [ 3405.667929] CPU: 3 PID: 2261 Comm: hexchat Not tainted 4.4.0-21-generic #37-Ubuntu [ 3405.667998] Hardware name: /NUC6i3SYB, BIOS SYSKLi35.86A.0042.2016.0409.1246 04/09/2016 [ 3405.668082] task: ffff88003565ac40 ti: ffff8804332e8000 task.ti: ffff8804332e8000 [ 3405.668148] RIP: 0010:[<ffffffff811eb027>] [<ffffffff811eb027>] kmem_cache_alloc+0x77/0x1f0 [ 3405.668234] RSP: 0018:ffff8804332eba88 EFLAGS: 00010282 [ 3405.668282] RAX: 0000000000000000 RBX: 0000000002408040 RCX: 00000000000e1547 [ 3405.668345] RDX: 00000000000e1546 RSI: 0000000002408040 RDI: 000000000001a940 [ 3405.668408] RBP: ffff8804332ebab8 R08: ffff88046ed9a940 R09: ffdb88033bb3a3a8 [ 3405.668470] R10: ffff8804591a4ed0 R11: ffffffff81ccc462 R12: 0000000002408040 [ 3405.668533] R13: ffffffff81243351 R14: ffff88045e08bc00 R15: ffff88045e08bc00 [ 3405.668597] FS: 00007f1df9704a40(0000) GS:ffff88046ed80000(0000) knlGS:0000000000000000 [ 3405.668668] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3405.668719] CR2: 00007fd945ecebd6 CR3: 0000000456a48000 CR4: 00000000003406e0 [ 3405.668782] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 3405.668844] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 3405.668906] Stack: [ 3405.668926] 01ff880438ee2508 0000000000001000 ffff8803344df000 ffffea000cd137c0 [ 3405.669003] 0000000000000000 0000000000000000 ffff8804332ebad0 ffffffff81243351 [ 3405.669080] ffff8800354bd024 ffff8804332ebb18 ffffffff81243829 00000001332ebb70 [ 3405.669156] Call Trace: [ 3405.669186] [<ffffffff81243351>] alloc_buffer_head+0x21/0x60 [ 3405.669240] [<ffffffff81243829>] alloc_page_buffers+0x79/0xe0 [ 3405.669294] [<ffffffff812438ae>] create_empty_buffers+0x1e/0xc0 [ 3405.669351] [<ffffffff812979cc>] ext4_block_write_begin+0x3cc/0x4d0 [ 3405.669410] [<ffffffff812e74db>] ? jbd2__journal_start+0xdb/0x1e0 [ 3405.669469] [<ffffffff81296e10>] ? ext4_inode_attach_jinode.part.60+0xb0/0xb0 [ 3405.669536] [<ffffffff812cb83d>] ? __ext4_journal_start_sb+0x6d/0x120 [ 3405.669596] [<ffffffff8129d574>] ext4_da_write_begin+0x154/0x320 [ 3405.669656] [<ffffffff8118d4de>] generic_perform_write+0xce/0x1c0 [ 3405.669713] [<ffffffff8118f382>] __generic_file_write_iter+0x1a2/0x1e0 [ 3405.669773] [<ffffffff81291ffc>] ext4_file_write_iter+0xfc/0x460 [ 3405.669833] [<ffffffff81794d6e>] ? inet_recvmsg+0x7e/0xb0 [ 3405.669885] [<ffffffff816fdb6b>] ? sock_recvmsg+0x3b/0x50 [ 3405.669938] [<ffffffff8120bedb>] new_sync_write+0x9b/0xe0 [ 3405.669990] [<ffffffff8120bf46>] __vfs_write+0x26/0x40 [ 3405.670040] [<ffffffff8120c8c9>] vfs_write+0xa9/0x1a0 [ 3405.672397] [<ffffffff8120c776>] ? vfs_read+0x86/0x130 [ 3405.674693] [<ffffffff8120d585>] SyS_write+0x55/0xc0 [ 3405.676925] [<ffffffff818244f2>] entry_SYSCALL_64_fastpath+0x16/0x71 [ 3405.679111] Code: 08 65 4c 03 05 83 f1 e1 7e 49 83 78 10 00 4d 8b 08 0f 84 29 01 00 00 4d 85 c9 0f 84 20 01 00 00 49 63 47 20 48 8d 4a 01 49 8b 3f <49> 8b 1c 01 4c 89 c8 65 48 0f c7 0f 0f 94 c0 84 c0 74 bb 49 63 [ 3405.683725] RIP [<ffffffff811eb027>] kmem_cache_alloc+0x77/0x1f0 [ 3405.685876] RSP <ffff8804332eba88> [ 3405.696001] ---[ end trace 4968a9119e168c92 ]--- After this occurs, the system becomes extremely unstable, i.e., the filesystem cannot be read properly anymore (e.g., ssh logins usually do not work anymore, most binaries just segfault). After a reboot (which has to be done manually, "shutdown -r now" also segfaults) it works fine again (until the problem comes back). Since the hardware is fairly new, I cannot exclude a hardware defect as of now. I've thouroughly tested the RAM though and not found any defect there (ran MemTest86+ for 24 hours). One curious thing is that someone else seems to have run into this before. Searching for the symbols in the stackframe I came upon this: http://pastebin.com/BJbu35H4 Which, quoting in full: Jul 16 14:28:29 nuc kernel: [ 370.642612] general protection fault: 0000 [#1] SMP Jul 16 14:28:29 nuc kernel: [ 370.642657] Modules linked in: arc4 intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel iwlmvm kvm mac80211 irqbypass crct10dif_pclmul crc32_pclmul iwlwifi aesni_intel aes_x86_64 snd_hda_codec_hdmi btusb btrtl snd_hda_codec_realtek btbcm btintel lrw gf128mul snd_hda_codec_generic ir_xmp_decoder glue_helper ablk_helper ir_lirc_codec cryptd mei_me lirc_dev ir_mce_kbd_decoder ir_sharp_decoder ir_sanyo_decoder bluetooth cfg80211 snd_hda_intel ir_sony_decoder mei ir_jvc_decoder ir_rc6_decoder ir_rc5_decoder ir_nec_decoder lpc_ich snd_hda_codec shpchp snd_soc_rt5640 snd_hda_core snd_soc_rl6231 snd_hwdep snd_soc_core snd_compress ac97_bus snd_pcm_dmaengine rc_rc6_mce dw_dmac snd_pcm nuvoton_cir rc_core snd_timer dw_dmac_core snd elan_i2c soundcore snd_soc_sst_acpi spi_pxa2xx_platform i2c_designware_platform i2c_designware_core 8250_dw mac_hid ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 xt_hl ip6t_rt nf_conntrack_ipv6 nf_defrag_ipv6 ipt_REJECT nf_reject_ipv4 xt_comment nf_log_ipv4 nf_log_common xt_LOG xt_multiport xt_limit xt_tcpudp xt_addrtype nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack ip6table_filter ip6_tables nf_conntrack_netbios_ns nf_conntrack_broadcast nf_nat_ftp nf_nat sunrpc nf_conntrack_ftp nf_conntrack iptable_filter ip_tables x_tables autofs4 btrfs xor raid6_pq i915 i2c_algo_bit drm_kms_helper e1000e syscopyarea sysfillrect sysimgblt uas fb_sys_fops ptp ahci sdhci_acpi usb_storage libahci drm pps_core video i2c_hid sdhci hid fjes Jul 16 14:28:29 nuc kernel: [ 370.643778] CPU: 3 PID: 1505 Comm: dd Not tainted 4.4.0-31-generic #50-Ubuntu Jul 16 14:28:29 nuc kernel: [ 370.643822] Hardware name: /D54250WYK, BIOS WYLPT10H.86A.0041.2015.0720.1108 07/20/2015 Jul 16 14:28:29 nuc kernel: [ 370.643878] task: ffff88040aa90000 ti: ffff880407b98000 task.ti: ffff880407b98000 Jul 16 14:28:29 nuc kernel: [ 370.643923] RIP: 0010:[<ffffffff811eb987>] [<ffffffff811eb987>] kmem_cache_alloc+0x77/0x1f0 Jul 16 14:28:29 nuc kernel: [ 370.643982] RSP: 0018:ffff880407b9ba80 EFLAGS: 00010282 Jul 16 14:28:29 nuc kernel: [ 370.644015] RAX: 0000000000000000 RBX: 0000000002408040 RCX: 00000000000bb283 Jul 16 14:28:29 nuc kernel: [ 370.644054] RDX: 00000000000bb282 RSI: 0000000002408040 RDI: 000000000001a940 Jul 16 14:28:29 nuc kernel: [ 370.644076] RBP: ffff880407b9bab0 R08: ffff88041fb9a940 R09: ddff88007f5aff08 Jul 16 14:28:29 nuc kernel: [ 370.644097] R10: ffff8800d522d060 R11: ffffffff81ccf1ea R12: 0000000002408040 Jul 16 14:28:29 nuc kernel: [ 370.644119] R13: ffffffff81243ea1 R14: ffff88040f08bc00 R15: ffff88040f08bc00 Jul 16 14:28:29 nuc kernel: [ 370.644141] FS: 00007fa227587700(0000) GS:ffff88041fb80000(0000) knlGS:0000000000000000 Jul 16 14:28:29 nuc kernel: [ 370.644165] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jul 16 14:28:29 nuc kernel: [ 370.644183] CR2: 0000000000a08000 CR3: 000000040aaac000 CR4: 00000000001406e0 Jul 16 14:28:29 nuc kernel: [ 370.644205] Stack: Jul 16 14:28:29 nuc kernel: [ 370.644213] 01ff8803fef10a00 0000000000001000 ffff88007b89f000 ffffea0001ee27c0 Jul 16 14:28:29 nuc kernel: [ 370.644241] 0000000000000000 0000000000000000 ffff880407b9bac8 ffffffff81243ea1 Jul 16 14:28:29 nuc kernel: [ 370.644270] ffff8804099b8024 ffff880407b9bb10 ffffffff81244379 0000000107b9bb68 Jul 16 14:28:29 nuc kernel: [ 370.644298] Call Trace: Jul 16 14:28:29 nuc kernel: [ 370.644311] [<ffffffff81243ea1>] alloc_buffer_head+0x21/0x60 Jul 16 14:28:29 nuc kernel: [ 370.644329] [<ffffffff81244379>] alloc_page_buffers+0x79/0xe0 Jul 16 14:28:29 nuc kernel: [ 370.644349] [<ffffffff812443fe>] create_empty_buffers+0x1e/0xc0 Jul 16 14:28:29 nuc kernel: [ 370.644369] [<ffffffff812987fc>] ext4_block_write_begin+0x3cc/0x4e0 Jul 16 14:28:29 nuc kernel: [ 370.644390] [<ffffffff812e8afb>] ? jbd2__journal_start+0xdb/0x1e0 Jul 16 14:28:29 nuc kernel: [ 370.644410] [<ffffffff81297c40>] ? ext4_inode_attach_jinode.part.60+0xb0/0xb0 Jul 16 14:28:29 nuc kernel: [ 370.644434] [<ffffffff812ccc2d>] ? __ext4_journal_start_sb+0x6d/0x120 Jul 16 14:28:29 nuc kernel: [ 370.644456] [<ffffffff8129e61d>] ext4_da_write_begin+0x15d/0x340 Jul 16 14:28:29 nuc kernel: [ 370.644477] [<ffffffff8118db4e>] generic_perform_write+0xce/0x1c0 Jul 16 14:28:29 nuc kernel: [ 370.644498] [<ffffffff8118f9f2>] __generic_file_write_iter+0x1a2/0x1e0 Jul 16 14:28:29 nuc kernel: [ 370.644518] [<ffffffff81292d72>] ext4_file_write_iter+0x102/0x470 Jul 16 14:28:29 nuc kernel: [ 370.644540] [<ffffffff81403f37>] ? iov_iter_zero+0x67/0x200 Jul 16 14:28:29 nuc kernel: [ 370.644560] [<ffffffff8120c94b>] new_sync_write+0x9b/0xe0 Jul 16 14:28:29 nuc kernel: [ 370.644578] [<ffffffff8120c9b6>] __vfs_write+0x26/0x40 Jul 16 14:28:29 nuc kernel: [ 370.645377] [<ffffffff8120d339>] vfs_write+0xa9/0x1a0 Jul 16 14:28:29 nuc kernel: [ 370.646174] [<ffffffff8120d274>] ? vfs_read+0x114/0x130 Jul 16 14:28:29 nuc kernel: [ 370.646973] [<ffffffff8120dff5>] SyS_write+0x55/0xc0 Jul 16 14:28:29 nuc kernel: [ 370.647766] [<ffffffff8182db32>] entry_SYSCALL_64_fastpath+0x16/0x71 Jul 16 14:28:29 nuc kernel: [ 370.648547] Code: 08 65 4c 03 05 23 e8 e1 7e 49 83 78 10 00 4d 8b 08 0f 84 29 01 00 00 4d 85 c9 0f 84 20 01 00 00 49 63 47 20 48 8d 4a 01 49 8b 3f <49> 8b 1c 01 4c 89 c8 65 48 0f c7 0f 0f 94 c0 84 c0 74 bb 49 63 Jul 16 14:28:29 nuc kernel: [ 370.650215] RIP [<ffffffff811eb987>] kmem_cache_alloc+0x77/0x1f0 Jul 16 14:28:29 nuc kernel: [ 370.650985] RSP <ffff880407b9ba80> Jul 16 14:28:29 nuc kernel: [ 370.651755] ---[ end trace 639091250fabe2af ]--- Shows also a stacktrace with the same call path, also running on a (different) Intel NUC, also running a 4.4.0 kernel. This pastebin is nowhere referenced however, so I'm unsure who found it and where exactly it was posted. Since the offending process in the unknown guy or girl's pastebin was dd, however, I believe that he or she tried to deliberately reproduce the problem. The problem occurs only when the system is under heavy disk load for me (usually after an hour of activity). I've a process running which frequently does sqlite3 commits about every 10 seconds. Having it run overnight with almost no load led to no oooops. Any and all advice is greatly appreciated. Cheers, Johannes -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
