Red Hat Bugzilla – Bug 197838
circular locking dependency
Last modified: 2007-11-30 17:11:36 EST
This is with Jul 6 09:26:54 dhcp83-51 kernel: Linux version 2.6.17-1.2356.fc6 (brewbuilder@hs20-bc2-4.build.redhat.com) (gcc version 4.1.1 20060629 (Red Hat 4.1.1-6)) #1 SMP Thu Jul 6 01:10:48 EDT 2006 J The /var/log/message entry reads: Jul 6 09:26:56 dhcp83-51 kernel: ======================================================= Jul 6 09:26:56 dhcp83-51 kernel: [ INFO: possible circular locking dependency detected ] Jul 6 09:26:56 dhcp83-51 kernel: ------------------------------------------------------- Jul 6 09:26:56 dhcp83-51 kernel: S06cpuspeed/1838 is trying to acquire lock: Jul 6 09:26:56 dhcp83-51 kernel: (dbs_mutex){--..}, at: [<c060d6bb>] mutex_lock+0x21/0x24 Jul 6 09:26:56 dhcp83-51 kernel: Jul 6 09:26:56 dhcp83-51 kernel: but task is already holding lock: Jul 6 09:26:56 dhcp83-51 kernel: (cpucontrol){--..}, at: [<c060d6bb>] mutex_lock+0x21/0x24 Jul 6 09:26:56 dhcp83-51 kernel: Jul 6 09:26:56 dhcp83-51 kernel: which lock already depends on the new lock. Jul 6 09:26:56 dhcp83-51 kernel: Jul 6 09:26:56 dhcp83-51 kernel: Jul 6 09:26:56 dhcp83-51 kernel: the existing dependency chain (in reverse order) is: Jul 6 09:26:56 dhcp83-51 kernel: Jul 6 09:26:56 dhcp83-51 kernel: -> #1 (cpucontrol){--..}: Jul 6 09:26:56 dhcp83-51 kernel: [<c043c546>] lock_acquire+0x4b/0x6d Jul 6 09:26:56 dhcp83-51 kernel: [<c060d51e>] __mutex_lock_slowpath+0xbf/0x23b Jul 6 09:26:56 dhcp83-51 kernel: [<c060d6bb>] mutex_lock+0x21/0x24 Jul 6 09:26:56 dhcp83-51 kernel: [<c0440009>] __lock_cpu_hotplug+0x36/0x56 Jul 6 09:26:56 dhcp83-51 kernel: [<c0440042>] lock_cpu_hotplug+0xa/0xc Jul 6 09:26:56 dhcp83-51 kernel: [<c04337de>] __create_workqueue+0x52/0x168 Jul 6 09:26:56 dhcp83-51 kernel: [<f8b9832e>] cpufreq_governor_dbs+0x9e/0x2cb [cpufreq_ondemand] Jul 6 09:26:56 dhcp83-51 kernel: [<c05a724b>] __cpufreq_governor+0x57/0xd8 Jul 6 09:26:56 dhcp83-51 kernel: [<c05a7409>] __cpufreq_set_policy+0x13d/0x1a9 Jul 6 09:26:56 dhcp83-51 kernel: [<c05a760c>] store_scaling_governor+0x128/0x151 Jul 6 09:26:56 dhcp83-51 kernel: [<c05a6c67>] store+0x37/0x48 Jul 6 09:26:56 dhcp83-51 kernel: [<c04ab4cc>] sysfs_write_file+0xab/0xd1 Jul 6 09:26:56 dhcp83-51 kernel: [<c047248b>] vfs_write+0xab/0x157 Jul 6 09:26:56 dhcp83-51 kernel: [<c0472ace>] sys_write+0x3b/0x60 Jul 6 09:26:56 dhcp83-51 kernel: [<c0403f2f>] syscall_call+0x7/0xb Jul 6 09:26:56 dhcp83-51 kernel: Jul 6 09:26:56 dhcp83-51 kernel: -> #0 (dbs_mutex){--..}: Jul 6 09:26:56 dhcp83-51 kernel: [<c043c546>] lock_acquire+0x4b/0x6d Jul 6 09:26:56 dhcp83-51 kernel: [<c060d51e>] __mutex_lock_slowpath+0xbf/0x23b Jul 6 09:26:56 dhcp83-51 kernel: [<c060d6bb>] mutex_lock+0x21/0x24 Jul 6 09:26:56 dhcp83-51 kernel: [<f8b98503>] cpufreq_governor_dbs+0x273/0x2cb [cpufreq_ondemand] Jul 6 09:26:56 dhcp83-51 kernel: [<c05a724b>] __cpufreq_governor+0x57/0xd8 Jul 6 09:26:56 dhcp83-51 kernel: [<c05a7463>] __cpufreq_set_policy+0x197/0x1a9 Jul 6 09:26:56 dhcp83-51 kernel: [<c05a760c>] store_scaling_governor+0x128/0x151 Jul 6 09:26:56 dhcp83-51 kernel: [<c05a6c67>] store+0x37/0x48 Jul 6 09:26:56 dhcp83-51 kernel: [<c04ab4cc>] sysfs_write_file+0xab/0xd1 Jul 6 09:26:56 dhcp83-51 kernel: [<c047248b>] vfs_write+0xab/0x157 Jul 6 09:26:56 dhcp83-51 kernel: [<c0472ace>] sys_write+0x3b/0x60 Jul 6 09:26:56 dhcp83-51 kernel: [<c0403f2f>] syscall_call+0x7/0xb Jul 6 09:26:56 dhcp83-51 kernel: Jul 6 09:26:56 dhcp83-51 kernel: other info that might help us debug this: Jul 6 09:26:56 dhcp83-51 kernel: Jul 6 09:26:56 dhcp83-51 kernel: 2 locks held by S06cpuspeed/1838: Jul 6 09:26:56 dhcp83-51 kernel: #0: (&policy->lock){--..}, at: [<c060d6bb>] mutex_lock+0x21/0x24 Jul 6 09:26:56 dhcp83-51 kernel: #1: (cpucontrol){--..}, at: [<c060d6bb>] mutex_lock+0x21/0x24 Jul 6 09:26:56 dhcp83-51 kernel: Jul 6 09:26:56 dhcp83-51 kernel: stack backtrace: Jul 6 09:26:56 dhcp83-51 kernel: [<c0405167>] show_trace_log_lvl+0x54/0xfd Jul 6 09:26:56 dhcp83-51 kernel: [<c040571e>] show_trace+0xd/0x10 Jul 6 09:26:56 dhcp83-51 kernel: [<c040583d>] dump_stack+0x19/0x1b Jul 6 09:26:56 dhcp83-51 kernel: [<c043b63d>] print_circular_bug_tail+0x59/0x64 Jul 6 09:26:56 dhcp83-51 kernel: [<c043be35>] __lock_acquire+0x7ed/0x98d Jul 6 09:26:56 dhcp83-51 kernel: [<c043c546>] lock_acquire+0x4b/0x6d Jul 6 09:26:56 dhcp83-51 kernel: [<c060d51e>] __mutex_lock_slowpath+0xbf/0x23b Jul 6 09:26:56 dhcp83-51 kernel: [<c060d6bb>] mutex_lock+0x21/0x24 Jul 6 09:26:56 dhcp83-51 kernel: [<f8b98503>] cpufreq_governor_dbs+0x273/0x2cb [cpufreq_ondemand] Jul 6 09:26:56 dhcp83-51 kernel: [<c05a724b>] __cpufreq_governor+0x57/0xd8 Jul 6 09:26:56 dhcp83-51 kernel: [<c05a7463>] __cpufreq_set_policy+0x197/0x1a9 Jul 6 09:26:56 dhcp83-51 kernel: [<c05a760c>] store_scaling_governor+0x128/0x151 Jul 6 09:26:56 dhcp83-51 kernel: [<c05a6c67>] store+0x37/0x48 Jul 6 09:26:56 dhcp83-51 hcid[2413]: Bluetooth HCI daemon Jul 6 09:26:56 dhcp83-51 kernel: [<c04ab4cc>] sysfs_write_file+0xab/0xd1 Jul 6 09:26:56 dhcp83-51 kernel: [<c047248b>] vfs_write+0xab/0x157 Jul 6 09:26:56 dhcp83-51 kernel: [<c0472ace>] sys_write+0x3b/0x60
*** This bug has been marked as a duplicate of 197803 ***