========================================================= [ INFO: possible irq lock inversion dependency detected ] 2.6.20-2925.9.fc7xen #1 --------------------------------------------------------- loader/210 just changed the state of lock: (&np->rx_lock){-...}, at: [] network_open+0x28/0x83 [xennet] but this lock was taken by another, hard-irq-safe lock in the past: (&np->tx_lock){+...} / between elements | selects | next screen and interrupts could create inverse lock ordering between them. other info that might help us debug this: 1 lock held by loader/210: #0: (rtnl_mutex){--..}, at: [] mutex_lock+0x21/0x24 the first lock's dependencies: -> (&np->rx_lock){-...} ops: 0 { initial-use at: [] __lock_acquire+0x438/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] backend_changed+0x65a/0x7b1 [xennet] [] otherend_changed+0x84/0x8a [] xenwatch_handle_callback+0x15/0x45 [] xenwatch_thread+0xfd/0x114 [] kthread+0xb3/0xdc [] kernel_thread_helper+0x7/0x10 [] 0xffffffff hardirq-on-W at: [] __lock_acquire+0x3f3/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] network_open+0x28/0x83 [xennet] [] dev_open+0x2e/0x66 [] dev_change_flags+0x51/0xf1 [] devinet_ioctl+0x235/0x53b [] inet_ioctl+0x73/0x91 [] sock_ioctl+0x1ac/0x1c9 [] do_ioctl+0x22/0x67 [] vfs_ioctl+0x252/0x265 [] sys_ioctl+0x49/0x64 [] syscall_call+0x7/0xb [] 0xffffffff } ... key at: [] __key.29552+0x0/0xffffb476 [xennet] -> (lweventlist_lock){....} ops: 0 { initial-use at: [] __lock_acquire+0x438/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock_irqsave+0x38/0x48 [] linkwatch_fire_event+0x5c/0xb1 [] netif_carrier_off+0x18/0x1a [] netfront_probe+0x51/0x2e3 [xennet] [] xenbus_dev_probe+0x51/0xb4 [] really_probe+0x80/0x104 [] driver_probe_device+0x95/0xa1 [] __driver_attach+0x76/0xaf [] bus_for_each_dev+0x3a/0x5f [] driver_attach+0x19/0x1b [] bus_add_driver+0x6a/0x170 [] driver_register+0x79/0x7e [] xenbus_register_driver_common+0x2e/0x3f [] xenbus_register_frontend+0x1b/0x2e [] 0xd1023070 [] sys_init_module+0x173e/0x1899 [] syscall_call+0x7/0xb [] 0xffffffff } ... key at: [] lweventlist_lock+0x10/0x1c ... acquired at: [] __lock_acquire+0x8ef/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock_irqsave+0x38/0x48 [] linkwatch_fire_event+0x5c/0xb1 [] netif_carrier_on+0x19/0x2a [] backend_changed+0x75f/0x7b1 [xennet] [] otherend_changed+0x84/0x8a [] xenwatch_handle_callback+0x15/0x45 [] xenwatch_thread+0xfd/0x114 [] kthread+0xb3/0xdc [] kernel_thread_helper+0x7/0x10 [] 0xffffffff -> (base_lock_keys + cpu){.+..} ops: 0 { initial-use at: [] __lock_acquire+0x438/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock_irqsave+0x38/0x48 [] lock_timer_base+0x18/0x33 [] __mod_timer+0x20/0xa3 [] mod_timer+0x21/0x27 [] con_init+0xb9/0x203 [] console_init+0x1e/0x2c [] start_kernel+0x1e5/0x3ea [] 0xc1000079 [] 0xffffffff in-softirq-W at: [] __lock_acquire+0x38e/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock_irq+0x35/0x42 [] run_timer_softirq+0x39/0x168 [] __do_softirq+0x73/0xea [] do_softirq+0x65/0xd1 [] 0xffffffff } ... key at: [] base_lock_keys+0x0/0x100 ... acquired at: [] __lock_acquire+0x8ef/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock_irqsave+0x38/0x48 [] lock_timer_base+0x18/0x33 [] __mod_timer+0x20/0xa3 [] queue_delayed_work+0x72/0x7e [] schedule_delayed_work+0x11/0x13 [] linkwatch_fire_event+0xab/0xb1 [] netif_carrier_on+0x19/0x2a [] backend_changed+0x75f/0x7b1 [xennet] [] otherend_changed+0x84/0x8a [] xenwatch_handle_callback+0x15/0x45 [] xenwatch_thread+0xfd/0x114 [] kthread+0xb3/0xdc [] kernel_thread_helper+0x7/0x10 [] 0xffffffff -> (&parent->list_lock){.+..} ops: 0 { initial-use at: [] __lock_acquire+0x438/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] cache_alloc_refill+0x5c/0x47d [] kmem_cache_zalloc+0x6b/0xbc [] kmem_cache_create+0x178/0x4b2 [] kmem_cache_init+0x16a/0x41e [] start_kernel+0x256/0x3ea [] 0xc1000079 [] 0xffffffff in-softirq-W at: [] __lock_acquire+0x38e/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] cache_flusharray+0x25/0xa8 [] kmem_cache_free+0x62/0x92 [] free_task+0x21/0x24 [] __put_task_struct+0x104/0x10a [] delayed_put_task_struct+0x1e/0x20 [] __rcu_process_callbacks+0x107/0x17f [] rcu_process_callbacks+0x1f/0x3d [] tasklet_action+0x63/0xd3 [] __do_softirq+0x73/0xea [] do_softirq+0x65/0xd1 [] 0xffffffff } ... key at: [] __key.17782+0x0/0x8 -> (&zone->lock){.+..} ops: 0 { initial-use at: [] __lock_acquire+0x438/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] __free_pages_ok+0x12a/0x288 [] __free_pages+0x2e/0x30 [] __free_pages_bootmem+0x9c/0xa0 [] free_all_bootmem_core+0xaf/0x147 [] free_all_bootmem+0xd/0xf [] mem_init+0x14e/0x4d8 [] start_kernel+0x251/0x3ea [] 0xc1000079 [] 0xffffffff in-softirq-W at: [] __lock_acquire+0x38e/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] __free_pages_ok+0x12a/0x288 [] __free_pages+0x2e/0x30 [] free_pages+0x29/0x2b [] kmem_freepages+0xaa/0xb0 [] slab_destroy+0x70/0x8c [] free_block+0xb3/0xe8 [] cache_flusharray+0x7a/0xa8 [] kmem_cache_free+0x62/0x92 [] free_task+0x21/0x24 [] __put_task_struct+0x104/0x10a [] delayed_put_task_struct+0x1e/0x20 [] __rcu_process_callbacks+0x107/0x17f [] rcu_process_callbacks+0x1f/0x3d [] tasklet_action+0x63/0xd3 [] __do_softirq+0x73/0xea [] do_softirq+0x65/0xd1 [] 0xffffffff } ... key at: [] __key.22301+0x0/0xc ... acquired at: [] __lock_acquire+0x8ef/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] __free_pages_ok+0x12a/0x288 [] __free_pages+0x2e/0x30 [] free_pages+0x29/0x2b [] kmem_freepages+0xaa/0xb0 [] slab_destroy+0x70/0x8c [] free_block+0xb3/0xe8 [] cache_flusharray+0x7a/0xa8 [] kmem_cache_free+0x62/0x92 [] free_task+0x21/0x24 [] __put_task_struct+0x104/0x10a [] delayed_put_task_struct+0x1e/0x20 [] __rcu_process_callbacks+0x107/0x17f [] rcu_process_callbacks+0x1f/0x3d [] tasklet_action+0x63/0xd3 [] __do_softirq+0x73/0xea [] do_softirq+0x65/0xd1 [] 0xffffffff -> (&on_slab_l3_key){.+..} ops: 0 { initial-use at: [] __lock_acquire+0x438/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] cache_alloc_refill+0x5c/0x47d [] kmem_cache_alloc+0x6b/0x9a [] request_irq+0x52/0xa1 [] bind_virq_to_irqhandler+0x118/0x135 [] setup_cpu0_timer_irq+0x3a/0x52 [] start_kernel+0x261/0x3ea [] 0xc1000079 [] 0xffffffff in-softirq-W at: [] __lock_acquire+0x38e/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] cache_flusharray+0x25/0xa8 [] kfree+0x6f/0x9f [] selinux_task_free_security+0x1a/0x1c [] __put_task_struct+0xab/0x10a [] delayed_put_task_struct+0x1e/0x20 [] __rcu_process_callbacks+0x107/0x17f [] rcu_process_callbacks+0x1f/0x3d [] tasklet_action+0x63/0xd3 [] __do_softirq+0x73/0xea [] do_softirq+0x65/0xd1 [] 0xffffffff } ... key at: [] on_slab_l3_key+0x0/0x8 ... acquired at: [] __lock_acquire+0x8ef/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] cache_flusharray+0x25/0xa8 [] kmem_cache_free+0x62/0x92 [] slab_destroy+0x86/0x8c [] free_block+0xb3/0xe8 [] cache_flusharray+0x7a/0xa8 [] kfree+0x6f/0x9f [] free_task+0xe/0x24 [] __put_task_struct+0x104/0x10a [] delayed_put_task_struct+0x1e/0x20 [] __rcu_process_callbacks+0x107/0x17f [] rcu_process_callbacks+0x1f/0x3d [] tasklet_action+0x63/0xd3 [] __do_softirq+0x73/0xea [] do_softirq+0x65/0xd1 [] 0xffffffff ... acquired at: [] __lock_acquire+0x8ef/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] cache_alloc_refill+0x5c/0x47d [] kmem_cache_alloc+0x6b/0x9a [] alloc_skb_from_cache+0x46/0x114 [] __alloc_skb+0x77/0x7e [] network_alloc_rx_buffers+0x5f/0x3e1 [xennet] [] backend_changed+0x77a/0x7b1 [xennet] [] otherend_changed+0x84/0x8a [] xenwatch_handle_callback+0x15/0x45 [] xenwatch_thread+0xfd/0x114 [] kthread+0xb3/0xdc [] kernel_thread_helper+0x7/0x10 [] 0xffffffff -> (&zone->lock){.+..} ops: 0 { initial-use at: [] __lock_acquire+0x438/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] __free_pages_ok+0x12a/0x288 [] __free_pages+0x2e/0x30 [] __free_pages_bootmem+0x9c/0xa0 [] free_all_bootmem_core+0xaf/0x147 [] free_all_bootmem+0xd/0xf [] mem_init+0x14e/0x4d8 [] start_kernel+0x251/0x3ea [] 0xc1000079 [] 0xffffffff in-softirq-W at: [] __lock_acquire+0x38e/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] __free_pages_ok+0x12a/0x288 [] __free_pages+0x2e/0x30 [] free_pages+0x29/0x2b [] kmem_freepages+0xaa/0xb0 [] slab_destroy+0x70/0x8c [] free_block+0xb3/0xe8 [] cache_flusharray+0x7a/0xa8 [] kmem_cache_free+0x62/0x92 [] free_task+0x21/0x24 [] __put_task_struct+0x104/0x10a [] delayed_put_task_struct+0x1e/0x20 [] __rcu_process_callbacks+0x107/0x17f [] rcu_process_callbacks+0x1f/0x3d [] tasklet_action+0x63/0xd3 [] __do_softirq+0x73/0xea [] do_softirq+0x65/0xd1 [] 0xffffffff } ... key at: [] __key.22301+0x0/0xc ... acquired at: [] __lock_acquire+0x8ef/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] get_page_from_freelist+0xeb/0x333 [] __alloc_pages+0xad/0x2e4 [] cache_alloc_refill+0x275/0x47d [] kmem_cache_alloc+0x6b/0x9a [] alloc_skb_from_cache+0x46/0x114 [] __alloc_skb+0x77/0x7e [] network_alloc_rx_buffers+0x5f/0x3e1 [xennet] [] backend_changed+0x77a/0x7b1 [xennet] [] otherend_changed+0x84/0x8a [] xenwatch_handle_callback+0x15/0x45 [] xenwatch_thread+0xfd/0x114 [] kthread+0xb3/0xdc [] kernel_thread_helper+0x7/0x10 [] 0xffffffff -> (balloon_lock){....} ops: 0 { initial-use at: [] __lock_acquire+0x438/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock_irqsave+0x38/0x48 [] balloon_update_driver_allowance+0x10/0x25 [] network_alloc_rx_buffers+0x304/0x3e1 [xennet] [] backend_changed+0x77a/0x7b1 [xennet] [] otherend_changed+0x84/0x8a [] xenwatch_handle_callback+0x15/0x45 [] xenwatch_thread+0xfd/0x114 [] kthread+0xb3/0xdc [] kernel_thread_helper+0x7/0x10 [] 0xffffffff } ... key at: [] balloon_lock+0x10/0x1c ... acquired at: [] __lock_acquire+0x8ef/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock_irqsave+0x38/0x48 [] balloon_update_driver_allowance+0x10/0x25 [] network_alloc_rx_buffers+0x304/0x3e1 [xennet] [] backend_changed+0x77a/0x7b1 [xennet] [] otherend_changed+0x84/0x8a [] xenwatch_handle_callback+0x15/0x45 [] xenwatch_thread+0xfd/0x114 [] kthread+0xb3/0xdc [] kernel_thread_helper+0x7/0x10 [] 0xffffffff the second lock's dependencies: -> (&np->tx_lock){+...} ops: 0 { initial-use at: [] __lock_acquire+0x438/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock_irq+0x35/0x42 [] backend_changed+0x64c/0x7b1 [xennet] [] otherend_changed+0x84/0x8a [] xenwatch_handle_callback+0x15/0x45 [] xenwatch_thread+0xfd/0x114 [] kthread+0xb3/0xdc [] kernel_thread_helper+0x7/0x10 [] 0xffffffff in-hardirq-W at: [] __lock_acquire+0x364/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock_irqsave+0x38/0x48 [] netif_int+0x19/0x68 [xennet] [] handle_IRQ_event+0x1a/0x4a [] handle_level_irq+0x9a/0xea [] do_IRQ+0xc6/0xee [] 0xffffffff } ... key at: [] __key.29551+0x0/0xffffb46e [xennet] -> (&np->rx_lock){-...} ops: 0 { initial-use at: [] __lock_acquire+0x438/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] backend_changed+0x65a/0x7b1 [xennet] [] otherend_changed+0x84/0x8a [] xenwatch_handle_callback+0x15/0x45 [] xenwatch_thread+0xfd/0x114 [] kthread+0xb3/0xdc [] kernel_thread_helper+0x7/0x10 [] 0xffffffff hardirq-on-W at: [] __lock_acquire+0x3f3/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock+0x2b/0x38 [] network_open+0x28/0x83 [xennet] [] dev_open+0x2e/0x66 [] dev_change_flags+0x51/0xf1 [] devinet_ioctl+0x235/0x53b [] inet_ioctl+0x73/0x91 [] sock_ioctl+0x1ac/0x1c9 [] do_ioctl+0x22/0x67 [] vfs_ioctl+0x252/0x265 [] sys_ioctl+0x49/0x64 [] syscall_call+0x7/0xb [] 0xffffffff } ... key at: [] __key.29552+0x0/0xffffb476 [xennet] -> (lweventlist_lock){....} ops: 0 { initial-use at: [] __lock_acquire+0x438/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock_irqsave+0x38/0x48 [] linkwatch_fire_event+0x5c/0xb1 [] netif_carrier_off+0x18/0x1a [] netfront_probe+0x51/0x2e3 [xennet] [] xenbus_dev_probe+0x51/0xb4 [] really_probe+0x80/0x104 [] driver_probe_device+0x95/0xa1 [] __driver_attach+0x76/0xaf [] bus_for_each_dev+0x3a/0x5f [] driver_attach+0x19/0x1b [] bus_add_driver+0x6a/0x170 [] driver_register+0x79/0x7e [] xenbus_register_driver_common+0x2e/0x3f [] xenbus_register_frontend+0x1b/0x2e [] 0xd1023070 [] sys_init_module+0x173e/0x1899 [] syscall_call+0x7/0xb [] 0xffffffff } ... key at: [] lweventlist_lock+0x10/0x1c ... acquired at: [] __lock_acquire+0x8ef/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock_irqsave+0x38/0x48 [] linkwatch_fire_event+0x5c/0xb1 [] netif_carrier_on+0x19/0x2a [] backend_changed+0x75f/0x7b1 [xennet] [] otherend_changed+0x84/0x8a [] xenwatch_handle_callback+0x15/0x45 [] xenwatch_thread+0xfd/0x114 [] kthread+0xb3/0xdc [] kernel_thread_helper+0x7/0x10 [] 0xffffffff -> (base_lock_keys + cpu){.+..} ops: 0 { initial-use at: [] __lock_acquire+0x438/0xa13 [] lock_acquire+0x61/0x80 [] _spin_lock_irqsave+0x38/0x48 [] lock_timer_base+0x18/0x33 [] __mod_timer+0x20/0xa3 [] mod_timer+0x21/0x27 [] con_init+0xb9/0x203 [] console_init+0x1e/0x2c [] start_kernel+0x1e5/0x3ea [] 0xc1000079 [] 0xffffffff in-softirq-W at: [] __lock_acquire+0x38e/0xa13 [