@Colin, sorry for the delay, I just checked and /sys/module/spl/parameters/spl_taskq_thread_dynamic defaults to 0 already.
That said, the issue happens only occasionally. Since I first reported it, there was only one other event during which it occurred several times in a row (between 2018-03-14 and 2018-03-15). I rebooted the VM and have yet to see it happen again. I still have the logs from those if that could be of any use to you. Thanks for taking such good care of ZoL for Ubuntu! ** Changed in: zfs-linux (Ubuntu) Status: Incomplete => Confirmed -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to zfs-linux in Ubuntu. https://bugs.launchpad.net/bugs/1749715 Title: general protection fault in zfs module Status in Native ZFS for Linux: New Status in zfs-linux package in Ubuntu: Confirmed Bug description: Got this call trace during a rsync backup of a machine using ZFS: general protection fault: 0000 [#1] SMP Modules linked in: ip6table_filter ip6_tables xt_tcpudp xt_conntrack iptable_filter ip_tables x_tables zfs(PO) zunicode(PO) zcommon(PO) znvpair(PO) spl(O) zavl(PO) input_leds sch_fq_codel nf_conntrack_ipv6 nf_defrag_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack virtio_scsi CPU: 0 PID: 4238 Comm: rsync Tainted: P O 4.4.0-112-generic #135-Ubuntu Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 task: ffff880078a4f2c0 ti: ffff880047c28000 task.ti: ffff880047c28000 RIP: 0010:[<ffffffffc03135b3>] [<ffffffffc03135b3>] avl_insert+0x33/0xe0 [zavl] RSP: 0018:ffff880047c2bc20 EFLAGS: 00010246 RAX: 0000000000000001 RBX: ffff880043b46200 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 001f880043b46208 RDI: ffff88005aa0c9a8 RBP: ffff880047c2bc20 R08: 0000000000000000 R09: ffff88007d001700 R10: ffff880043b46200 R11: 0000000000000246 R12: ffff88005aa0c9a8 R13: ffff880043b46200 R14: 0000000000000000 R15: ffff88005aa0c9a8 FS: 00007f04124ec700(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd25c1cb8c CR3: 0000000047cb0000 CR4: 0000000000000670 Stack: ffff880047c2bc68 ffffffffc0313721 0000000000000000 0020000000000008 ffff880043b46200 ffff88005aa0c8c8 0000000000006b34 0000000000000000 ffff88005aa0c9a8 ffff880047c2bcc8 ffffffffc04609ee 0000000000000000 Call Trace: [<ffffffffc0313721>] avl_add+0x71/0xa0 [zavl] [<ffffffffc04609ee>] zfs_range_lock+0x3ee/0x5e0 [zfs] [<ffffffffc0416e4c>] ? rrw_enter_read_impl+0xbc/0x160 [zfs] [<ffffffffc0465c90>] zfs_read+0xd0/0x3c0 [zfs] [<ffffffff9b39922d>] ? profile_path_perm.part.7+0x7d/0xa0 [<ffffffffc04818f0>] zpl_read_common_iovec+0x80/0xd0 [zfs] [<ffffffffc0482430>] zpl_iter_read+0xa0/0xd0 [zfs] [<ffffffff9b211134>] new_sync_read+0x94/0xd0 [<ffffffff9b211196>] __vfs_read+0x26/0x40 [<ffffffff9b211756>] vfs_read+0x86/0x130 [<ffffffff9b2124a5>] SyS_read+0x55/0xc0 [<ffffffff9b8456c7>] ? entry_SYSCALL_64_after_swapgs+0xd1/0x18c [<ffffffff9b8457ad>] entry_SYSCALL_64_fastpath+0x2b/0xe7 Code: 83 e2 01 48 03 77 10 49 83 e0 fe 8d 04 95 00 00 00 00 55 4c 89 c1 48 83 47 18 01 83 e0 04 48 83 c9 01 48 89 e5 48 09 c8 4d 85 c0 <48> c7 06 00 00 00 00 48 c7 46 08 00 00 00 00 48 89 46 10 0f 84 RIP [<ffffffffc03135b3>] avl_insert+0x33/0xe0 [zavl] RSP <ffff880047c2bc20> ---[ end trace c4ba4478b6002697 ]--- This is the first time it happens but I'll report any future occurrence in here. Additional info: $ lsb_release -rd Description: Ubuntu 16.04.3 LTS Release: 16.04 $ apt-cache policy linux-image-4.4.0-112-generic zfsutils-linux linux-image-4.4.0-112-generic: Installed: 4.4.0-112.135 Candidate: 4.4.0-112.135 Version table: *** 4.4.0-112.135 500 500 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages 500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages 100 /var/lib/dpkg/status zfsutils-linux: Installed: 0.6.5.6-0ubuntu18 Candidate: 0.6.5.6-0ubuntu18 Version table: *** 0.6.5.6-0ubuntu18 500 500 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages 100 /var/lib/dpkg/status 0.6.5.6-0ubuntu8 500 500 http://archive.ubuntu.com/ubuntu xenial/universe amd64 Packages ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-4.4.0-112-generic 4.4.0-112.135 ProcVersionSignature: Ubuntu 4.4.0-112.135-generic 4.4.98 Uname: Linux 4.4.0-112-generic x86_64 NonfreeKernelModules: zfs zunicode zcommon znvpair zavl AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Feb 14 16:19 seq crw-rw---- 1 root audio 116, 33 Feb 14 16:19 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.20.1-0ubuntu2.15 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: Error: [Errno 2] No such file or directory: 'fuser' CRDA: N/A CurrentDmesg: Error: command ['dmesg'] failed with exit code 1: dmesg: read kernel buffer failed: Operation not permitted Date: Thu Feb 15 08:45:07 2018 IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig' Lspci: Error: [Errno 2] No such file or directory: 'lspci' Lsusb: Error: [Errno 2] No such file or directory: 'lsusb' MachineType: QEMU Standard PC (i440FX + PIIX, 1996) PciMultimedia: ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 EFI VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-112-generic root=UUID=db4864d4-cc2e-40c7-bc2b-a14bc0f09c9f ro console=ttyS0 net.ifnames=0 kaslr nmi_watchdog=0 possible_cpus=1 vsyscall=none pti=on RelatedPackageVersions: linux-restricted-modules-4.4.0-112-generic N/A linux-backports-modules-4.4.0-112-generic N/A linux-firmware N/A RfKill: Error: [Errno 2] No such file or directory: 'rfkill' SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 04/01/2014 dmi.bios.vendor: SeaBIOS dmi.bios.version: Ubuntu-1.8.2-1ubuntu1 dmi.chassis.type: 1 dmi.chassis.vendor: QEMU dmi.chassis.version: pc-i440fx-2.5 dmi.modalias: dmi:bvnSeaBIOS:bvrUbuntu-1.8.2-1ubuntu1:bd04/01/2014:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-2.5:cvnQEMU:ct1:cvrpc-i440fx-2.5: dmi.product.name: Standard PC (i440FX + PIIX, 1996) dmi.product.version: pc-i440fx-2.5 dmi.sys.vendor: QEMU To manage notifications about this bug go to: https://bugs.launchpad.net/zfs/+bug/1749715/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp