This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:
apport-collect 1874266 and then change the status of the bug to 'Confirmed'. If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'. This change has been made by an automated script, maintained by the Ubuntu Kernel Team. ** Changed in: linux (Ubuntu) Status: New => Incomplete ** Tags added: xenial -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1874266 Title: Intensive NFS operations could lock whole system Status in linux package in Ubuntu: Incomplete Bug description: After last update from kernel version 4.4.0-176-generic to 4.4.0-177-generic my machine which does repository mirrors on NFS filesystem hung. After hang the system is pingable, and all processes run well until they need to perform IO operation. Then they end in 'D' state. If dmesg -w -H is run prior to hang you could get following report: [Apr22 16:06] INFO: task find:986 blocked for more than 120 seconds. [ +0.000034] Not tainted 4.4.0-177-generic #207-Ubuntu [ +0.000013] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ +0.000024] find D f4bbdd2c 0 986 721 0x00000000 [ +0.000010] f4bbdd1c 00000086 41ed78a0 f4bbdd2c eb5b7844 c1b36ec0 95907572 00000025 [ +0.000003] f4eb7e00 c1b1da80 f3ab6e00 f4bbe000 f3ab6e00 f53ae3a8 f4bbdd28 c17ec5cd [ +0.000002] 000001ff f4bbdd78 c11a8b57 f4bbdd3c f87bb75b f76ae800 f4bbdd50 f87b2bdd [ +0.000002] Call Trace: [ +0.000006] [<c17ec5cd>] schedule+0x2d/0x80 [ +0.000012] [<c11a8b57>] kmap_high+0x117/0x290 [ +0.000013] [<f87bb75b>] ? nfs_revalidate_inode_rcu+0x1b/0x40 [nfs] [ +0.000005] [<f87b2bdd>] ? nfs_check_verifier+0x6d/0x80 [nfs] [ +0.000004] [<c11d2c95>] ? kmem_cache_alloc_trace+0x185/0x1e0 [ +0.000012] [<c109ee50>] ? wake_up_q+0x70/0x70 [ +0.000003] [<c106bec0>] kmap+0x40/0x50 [ +0.000006] [<f87b4e0d>] nfs_readdir_xdr_to_array+0xdd/0x370 [nfs] [ +0.000005] [<f87b6835>] ? nfs4_lookup_revalidate+0x25/0x140 [nfs] [ +0.000002] [<c11e4d62>] ? mem_cgroup_commit_charge+0x62/0xe0 [ +0.000011] [<f87b50bb>] nfs_readdir_filler+0x1b/0x80 [nfs] [ +0.000002] [<c117e3b2>] do_read_cache_page+0x102/0x190 [ +0.000019] [<f87b50a0>] ? nfs_readdir_xdr_to_array+0x370/0x370 [nfs] [ +0.000002] [<c117e464>] read_cache_page+0x24/0x30 [ +0.000004] [<f87b5261>] nfs_readdir+0x141/0x740 [nfs] [ +0.000003] [<c13d21b6>] ? _copy_to_user+0x26/0x30 [ +0.000002] [<c135fba5>] ? common_file_perm+0x55/0x1b0 [ +0.000016] [<fbaac1c0>] ? nfs4_xdr_dec_fsinfo+0x80/0x80 [nfsv4] [ +0.000003] [<c1201c2e>] iterate_dir+0x8e/0x130 [ +0.000002] [<c120bde2>] ? set_close_on_exec+0x62/0x70 [ +0.000002] [<c120224d>] SyS_getdents64+0x6d/0xf0 [ +0.000001] [<c1201e10>] ? filldir+0x140/0x140 [ +0.000002] [<c100397f>] do_fast_syscall_32+0x9f/0x190 [ +0.000011] [<c17f08b0>] sysenter_past_esp+0x3d/0x61 [ +0.000002] INFO: task bash:1065 blocked for more than 120 seconds. [ +0.000015] Not tainted 4.4.0-177-generic #207-Ubuntu [ +0.000020] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ +0.000018] bash D 00000017 0 1065 760 0x00000000 [ +0.000002] f1b87e44 00000086 c11a799b 00000017 00000000 f1f1eff8 b37c5095 00000025 [ +0.000003] f4eb7e00 c1b1da80 f3ab3c00 f1b88000 f3ab3c00 f53b0298 f1b87e50 c17ec5cd [ +0.000002] 000001ff f1b87ea0 c11a8b57 f3ab3c00 f3131000 f3ab3c00 00000001 00000000 [ +0.000002] Call Trace: [ +0.000003] [<c11a799b>] ? follow_page_mask+0x16b/0x290 [ +0.000001] [<c17ec5cd>] schedule+0x2d/0x80 [ +0.000001] [<c11a8b57>] kmap_high+0x117/0x290 [ +0.000002] [<c109ee50>] ? wake_up_q+0x70/0x70 [ +0.000001] [<c106bec0>] kmap+0x40/0x50 [ +0.000002] [<c11f4ae8>] copy_strings+0x1f8/0x2d0 [ +0.000002] [<c11f4be6>] copy_strings_kernel+0x26/0x30 [ +0.000001] [<c11f5b29>] do_execveat_common+0x479/0x6f0 [ +0.000002] [<c11fd62a>] ? getname_flags+0x3a/0x1a0 [ +0.000001] [<c11f5fb4>] SyS_execve+0x34/0x40 [ +0.000002] [<c100397f>] do_fast_syscall_32+0x9f/0x190 [ +0.000002] [<c17f08b0>] sysenter_past_esp+0x3d/0x61 I did NOT noticed such behaviour on x86_64 architecture, only on i386. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1874266/+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