Btw,
while we're at it, I just discovered this in dmesg. Plain -rc3.
[34173.893305] ------------[ cut here ]------------ [34173.893321] WARNING: at kernel/mutex.c:199 mutex_lock_nested+0x39c/0x3b0() [34173.893328] Hardware name: To be filled by O.E.M. [34173.893333] Modules linked in: nls_iso8859_15 nls_cp437 fuse tun cpufreq_powersave cpufreq_userspace cpufreq_stats cpufreq_conservative dm_crypt dm_mod ipv6 vfat fat acpi_cpufreq mperf kvm_amd kvm crc32_pclmul aesni_intel aes_x86_64 ablk_helper cryptd xts lrw gf128mul microcode radeon amd64_edac_mod edac_core k10temp fam15h_power drm_kms_helper ttm cfbfillrect cfbimgblt r8169 cfbcopyarea [34173.893395] Pid: 15316, comm: kworker/0:0 Not tainted 3.9.0-rc3 #1 [34173.893402] Call Trace: [34173.893409] [<ffffffff8103b33f>] warn_slowpath_common+0x7f/0xc0 [34173.893417] [<ffffffff8103b39a>] warn_slowpath_null+0x1a/0x20 [34173.893424] [<ffffffff8159654c>] mutex_lock_nested+0x39c/0x3b0 [34173.893432] [<ffffffff8144b94d>] ? cpufreq_governor_dbs+0x3bd/0x560 [34173.893441] [<ffffffff8106bded>] ? __blocking_notifier_call_chain+0x7d/0xd0 [34173.893449] [<ffffffff8144b94d>] ? cpufreq_governor_dbs+0x3bd/0x560 [34173.893457] [<ffffffff81074ce1>] ? get_parent_ip+0x11/0x50 [34173.893464] [<ffffffff81074d99>] ? sub_preempt_count+0x79/0xd0 [34173.893472] [<ffffffff8144b94d>] cpufreq_governor_dbs+0x3bd/0x560 [34173.893480] [<ffffffff8144b24a>] od_cpufreq_governor_dbs+0x1a/0x20 [34173.893487] [<ffffffff81448f13>] __cpufreq_governor+0x53/0xf0 [34173.893494] [<ffffffff814494a5>] __cpufreq_set_policy+0x155/0x180 [34173.893502] [<ffffffff8144a483>] cpufreq_update_policy+0xf3/0x130 [34173.893510] [<ffffffff8144a4c0>] ? cpufreq_update_policy+0x130/0x130 [34173.893519] [<ffffffff8144a4d1>] handle_update+0x11/0x20 [34173.893526] [<ffffffff8105f3f7>] process_one_work+0x1f7/0x670 [34173.893533] [<ffffffff8105f38c>] ? process_one_work+0x18c/0x670 [34173.893541] [<ffffffff8105fbfe>] worker_thread+0x10e/0x370 [34173.893548] [<ffffffff8105faf0>] ? rescuer_thread+0x240/0x240 [34173.893556] [<ffffffff810654fb>] kthread+0xdb/0xe0 [34173.893563] [<ffffffff81071ba5>] ? finish_task_switch+0x85/0x110 [34173.893572] [<ffffffff81065420>] ? __init_kthread_worker+0x70/0x70 [34173.893579] [<ffffffff8159a71c>] ret_from_fork+0x7c/0xb0 [34173.893587] [<ffffffff81065420>] ? __init_kthread_worker+0x70/0x70 [34173.893594] ---[ end trace 66f5addf492b41b2 ]---