On 07/27/2011 02:37 PM, Thomas Gleixner wrote:
> Dear RT Folks,
>
> I'm pleased to announce the 3.0-rt4 release.

Testing rt5 (lenovo dual core laptop running fc15, kernel based on 
koji's 3.0.0 build plus rt5)...

----
[    0.000000] =============================================
[    0.000000] [ INFO: possible recursive locking detected ]
[    0.000000] 3.0.0-1.rt5.1.fc15.ccrma.i686.rtPAE #1
[    0.000000] ---------------------------------------------
[    0.000000] swapper/0 is trying to acquire lock:
[    0.000000]  (&parent->list_lock){+.+...}, at: [<c04fb406>] 
__cache_free+0x43/0xc3
[    0.000000]
[    0.000000] but task is already holding lock:
[    0.000000]  (&parent->list_lock){+.+...}, at: [<c04fc538>] 
do_tune_cpucache+0xf2/0x2bb
[    0.000000]
[    0.000000] other info that might help us debug this:
[    0.000000]  Possible unsafe locking scenario:
[    0.000000]
[    0.000000]        CPU0
[    0.000000]        ----
[    0.000000]   lock(&parent->list_lock);
[    0.000000]   lock(&parent->list_lock);
[    0.000000]
[    0.000000]  *** DEADLOCK ***
[    0.000000]
[    0.000000]  May be due to missing lock nesting notation
[    0.000000]
[    0.000000] 3 locks held by swapper/0:
[    0.000000]  #0:  (cache_chain_mutex){+.+...}, at: [<c0bd9d2b>] 
kmem_cache_init_late+0xe/0x61
[    0.000000]  #1:  (&per_cpu(slab_lock, __cpu).lock){+.+...}, at: 
[<c04faa65>] __local_lock_irq+0x1e/0x5b
[    0.000000]  #2:  (&parent->list_lock){+.+...}, at: [<c04fc538>] 
do_tune_cpucache+0xf2/0x2bb
[    0.000000]
[    0.000000] stack backtrace:
[    0.000000] Pid: 0, comm: swapper Not tainted 
3.0.0-1.rt5.1.fc15.ccrma.i686.rtPAE #1
[    0.000000] Call Trace:
[    0.000000]  [<c0856355>] ? printk+0x2d/0x2f
[    0.000000]  [<c0474a4b>] __lock_acquire+0x805/0xb57
[    0.000000]  [<c0472604>] ? lock_release_holdtime.part.10+0x4b/0x51
[    0.000000]  [<c085ecb4>] ? _raw_spin_unlock+0x31/0x3d
[    0.000000]  [<c085dbc5>] ? rt_spin_lock_slowlock+0x75/0x190
[    0.000000]  [<c04720c3>] ? trace_hardirqs_off+0xb/0xd
[    0.000000]  [<c04fb406>] ? __cache_free+0x43/0xc3
[    0.000000]  [<c0475215>] lock_acquire+0xde/0x11d
[    0.000000]  [<c04fb406>] ? __cache_free+0x43/0xc3
[    0.000000]  [<c085e24f>] rt_spin_lock+0x50/0x56
[    0.000000]  [<c04fb406>] ? __cache_free+0x43/0xc3
[    0.000000]  [<c04fb406>] __cache_free+0x43/0xc3
[    0.000000]  [<c043646d>] ? test_ti_thread_flag+0x8/0x10
[    0.000000]  [<c04fb23f>] kmem_cache_free+0x6c/0xdc
[    0.000000]  [<c04fb2fe>] slab_destroy+0x4f/0x53
[    0.000000]  [<c04fb396>] free_block+0x94/0xc1
[    0.000000]  [<c04fc551>] do_tune_cpucache+0x10b/0x2bb
[    0.000000]  [<c04fc8dc>] enable_cpucache+0x7b/0xa7
[    0.000000]  [<c0bd9d3c>] kmem_cache_init_late+0x1f/0x61
[    0.000000]  [<c0bba687>] start_kernel+0x24c/0x363
[    0.000000]  [<c0bba1c4>] ? loglevel+0x18/0x18
[    0.000000]  [<c0bba0ba>] i386_start_kernel+0xa9/0xaf
----

Full dmesg and config attached.

(I guess because HIGHMEM is disabled the computer only finds 800M+ of 
LOWMEM and that is all top reports - total installed is 4G)

-- Fernando