Hi folks, I received this for 3.0.4 (amd64) (see attachment for the complete kern.log). Sep 30 10:09:03 cecil kernel: [ 9345.593031] INFO: rcu_sched_state detected stall on CPU 6 (t=0 jiffies) Sep 30 10:09:03 cecil kernel: [ 9345.593035] sending NMI to all CPUs: Sep 30 10:09:03 cecil kernel: [ 9345.593040] NMI backtrace for cpu 6 Sep 30 10:09:03 cecil kernel: [ 9345.593043] CPU 6 : : ep 30 10:09:03 cecil kernel: [ 9345.593194] Call Trace: Sep 30 10:09:03 cecil kernel: [ 9345.593195] Sep 30 10:09:03 cecil kernel: [ 9345.593200] [] ? arch_trigger_all_cpu_backtrace+0x59/0x67 Sep 30 10:09:03 cecil kernel: [ 9345.593204] [] ? __rcu_pending+0x7e/0x337 Sep 30 10:09:03 cecil kernel: [ 9345.593208] [] ? tick_nohz_handler+0xcd/0xcd Sep 30 10:09:03 cecil kernel: [ 9345.593211] [] ? rcu_check_callbacks+0xbb/0x10a Sep 30 10:09:03 cecil kernel: [ 9345.593214] [] ? update_process_times+0x31/0x63 Sep 30 10:09:03 cecil kernel: [ 9345.593217] [] ? tick_sched_timer+0x67/0x8d Sep 30 10:09:03 cecil kernel: [ 9345.593219] [] ? __run_hrtimer.isra.28+0x4f/0xa8 Sep 30 10:09:03 cecil kernel: [ 9345.593222] [] ? hrtimer_interrupt+0xd5/0x1a1 Sep 30 10:09:03 cecil kernel: [ 9345.593225] [] ? smp_apic_timer_interrupt+0x7d/0x8f Sep 30 10:09:03 cecil kernel: [ 9345.593229] [] ? apic_timer_interrupt+0xe/0x20 Sep 30 10:09:03 cecil kernel: [ 9345.593231] [] ? apic_timer_interrupt+0x13/0x20 Sep 30 10:09:03 cecil kernel: [ 9345.593232] Sep 30 10:09:03 cecil kernel: [ 9345.593236] [] ? intel_idle+0xd1/0xed Sep 30 10:09:03 cecil kernel: [ 9345.593239] [] ? intel_idle+0xad/0xed Sep 30 10:09:03 cecil kernel: [ 9345.593242] [] ? cpuidle_idle_call+0x82/0xb9 Sep 30 10:09:03 cecil kernel: [ 9345.593245] [] ? cpu_idle+0x4e/0x99 Sep 30 10:09:03 cecil kernel: [ 9345.593246] Code: 0f 1f 84 00 00 00 00 00 48 ff c8 75 fb 48 ff c8 c3 48 8b 05 c8 40 2d 00 ff e0 48 8d 04 bd 00 00 00 00 65 48 8b 14 25 98 02 01 00 Sep 30 10:09:03 cecil kernel: [ 9345.593271] Call Trace: Sep 30 10:09:03 cecil kernel: [ 9345.593272] [] ? arch_trigger_all_cpu_backtrace+0x59/0x67 Sep 30 10:09:03 cecil kernel: [ 9345.593276] [] ? __rcu_pending+0x7e/0x337 Sep 30 10:09:03 cecil kernel: [ 9345.593279] [] ? tick_nohz_handler+0xcd/0xcd Sep 30 10:09:03 cecil kernel: [ 9345.593281] [] ? rcu_check_callbacks+0xbb/0x10a Sep 30 10:09:03 cecil kernel: [ 9345.593284] [] ? update_process_times+0x31/0x63 Sep 30 10:09:03 cecil kernel: [ 9345.593286] [] ? tick_sched_timer+0x67/0x8d Sep 30 10:09:03 cecil kernel: [ 9345.593288] [] ? __run_hrtimer.isra.28+0x4f/0xa8 Sep 30 10:09:03 cecil kernel: [ 9345.593291] [] ? hrtimer_interrupt+0xd5/0x1a1 Sep 30 10:09:03 cecil kernel: [ 9345.593293] [] ? smp_apic_timer_interrupt+0x7d/0x8f Sep 30 10:09:03 cecil kernel: [ 9345.593296] [] ? apic_timer_interrupt+0xe/0x20 Sep 30 10:09:03 cecil kernel: [ 9345.593298] [] ? apic_timer_interrupt+0x13/0x20 Sep 30 10:09:03 cecil kernel: [ 9345.593300] [] ? intel_idle+0xd1/0xed Sep 30 10:09:03 cecil kernel: [ 9345.593304] [] ? intel_idle+0xad/0xed Sep 30 10:09:03 cecil kernel: [ 9345.593307] [] ? cpuidle_idle_call+0x82/0xb9 Sep 30 10:09:03 cecil kernel: [ 9345.593309] [] ? cpu_idle+0x4e/0x99 : When the problem occured I was running an rsync of some huge files (>4 GByte each) from one USB device to another. It was already running for more than 2 hours. Please mail if I can help to track this down. Regards Harri