On a system in this condition, sometimes hung task traces are seen:
kernel: [65098.694112] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kernel: [65098.694117] cron D ffff880001885380 0 21248 569 0x00000000 kernel: [65098.694121] ffff880772e25d20 0000000000000282 0000000000000001 ffff880772e25ca0 kernel: [65098.694124] 0000000000000002 ffff880772e25ce8 ffff8802e100c678 ffff880772e25fd8 kernel: [65098.694126] ffff8802e100c2c0 ffff8802e100c2c0 ffff8802e100c2c0 ffff880772e25fd8 kernel: [65098.694128] Call Trace: kernel: [65098.694137] [<ffffffff810e312a>] ? cache_alloc_refill+0x6a/0x270 kernel: [65098.694141] [<ffffffff814a199d>] schedule_timeout+0x1dd/0x2c0 kernel: [65098.694145] [<ffffffff814a0b02>] wait_for_common+0xf2/0x1d0 kernel: [65098.694150] [<ffffffff81030260>] ? default_wake_function+0x0/0x10 kernel: [65098.694152] [<ffffffff814a0c78>] wait_for_completion+0x18/0x20 kernel: [65098.694156] [<ffffffff8103ba19>] do_fork+0x149/0x430 kernel: [65098.694160] [<ffffffff81109f04>] ? mntput_no_expire+0x24/0x110 kernel: [65098.694164] [<ffffffff810534e0>] ? set_one_prio+0x70/0xd0 kernel: [65098.694168] [<ffffffff8100fe60>] sys_vfork+0x20/0x30 kernel: [65098.694171] [<ffffffff81009f73>] stub_vfork+0x13/0x20 kernel: [65098.694174] [<ffffffff81009ba8>] ? system_call_fastpath+0x16/0x1b -- You received this bug notification because you are a member of Ubuntu Bugs, which is a direct subscriber. https://bugs.launchpad.net/bugs/708920 Title: Strange 'fork/clone' blocking behavior under high cpu usage on EC2 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
