[ltt-dev] LTTng 2.0 on ARM

[Mathieu Desnoyers]

* Mathieu Desnoyers (compudj at krystal.dyndns.org) wrote:
> * Avik Sil (avik.sil at linaro.org) wrote:
> > Hi Mathieu,
> > 
> > Now as the ARM patch is in, I'm able to generate trace and read the
> > trace with babeltrace on Pandaboard. But while enabling the events, I
> > get following output:
> > 
> > # lttng enable-event -a -k
> > [ 4304.827819] BUG: spinlock bad magic on CPU#1, ltt-sessiond/1305
> > [ 4304.841735]  lock: 81453c00, .magic: 00000000, .owner: <none>/-1,
> > .owner_cpu: 0
> > [ 4304.857421] [<800110ad>] (unwind_backtrace+0x1/0x90) from
> > [<8022c847>] (do_raw_spin_lock+0x17/0xfc)
> > [ 4304.875213] [<8022c847>] (do_raw_spin_lock+0x17/0xfc) from
> > [<7f97c30f>] (channel_create+0xd6/0x158 [lib_ring_buffer])
> > [ 4304.894866] [<7f97c30f>] (channel_create+0xd6/0x158
> > [lib_ring_buffer]) from [<7f99856b>] (_channel_create+0x28/0x32
> > [ltt_ring_buffer_client_discard])
> > [ 4304.917755] [<7f99856b>] (_channel_create+0x28/0x32
> > [ltt_ring_buffer_client_discard]) from [<7f98b507>]
> > (ltt_channel_create+0x12a/0x190 [ltt_relay])
> > [ 4304.940551] [<7f98b507>] (ltt_channel_create+0x12a/0x190 [ltt_relay])
> > from [<7f98c34b>] (lttng_abi_create_channel+0xba/0x158 [ltt_relay])
> > [ 4304.962341] [<7f98c34b>] (lttng_abi_create_channel+0xba/0x158
> > [ltt_relay]) from [<7f98c43f>] (lttng_session_ioctl+0x56/0x64 [ltt_relay])
> > [ 4304.984436] [<7f98c43f>] (lttng_session_ioctl+0x56/0x64 [ltt_relay])
> > from [<800baa49>] (do_vfs_ioctl+0x1a5/0x1dc)
> > [ 4305.004394] [<800baa49>] (do_vfs_ioctl+0x1a5/0x1dc) from [<800baab3>]
> > (sys_ioctl+0x33/0x4c)
> > [ 4305.022369] [<800baab3>] (sys_ioctl+0x33/0x4c) from [<8000c2c1>]
> > (ret_fast_syscall+0x1/0x50)
> > All kernel events are enabled in channel channel0
> > 
> > Can you please look into this issue?
> 
> Yes, it looks like I missed a spinlock initialization in there. Can you
> try with the following commit applied ?
> 
> commit 6fb8de4b6c1e8dcc69ff6f67310c5cf29718101a
> Author: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> Date:   Wed Sep 21 10:08:34 2011 -0400
> 
>     lib ring buffer frontend: add missing lock initialization

Silly me. Also make sure you have commit
02a766bbaa8b112e87d88aa4a70a507f5a6deb99, which marks the new init
function as a module_init().

Thanks,

Mathieu

> 
> Thanks,
> 
> Mathieu
> 
> > 
> > Regards,
> > Avik
> > 
> > On Sunday 11 September 2011 01:19 AM, Mathieu Desnoyers wrote:
> > > * Avik Sil (avik.sil at linaro.org) wrote:
> > >> Hi,
> > >>
> > >> I'm trying to use LTTng 2.0 on a Pandaboard. After building the latest
> > >> tools and modules I tried to run lttng and got following error:
> > >>
> > >> # lttng list -k
> > [...]
> > > 
> > > Hi Avik,
> > > 
> > > Can I get your kernel .config ? Also, adding a printk in lttng-modules
> > > wrapper/vmalloc.h, just after vmalloc_sync_all_sym = (void *)
> > > kallsyms_lookup_name("vmalloc_sync_all");
> > > 
> > > printing the vmalloc_sync_all_sym pointer value would be clearly
> > > helpful. I would think ARM does not implement vmalloc_sync_all, so the
> > > dummy mm/vmalloc.c vmalloc_sync_all weak symbol should be used as a
> > > valid empty function. Please grep for vmalloc_sync_all under your
> > > arch/arm to see if your particular omap flavor is implementing a
> > > vmalloc_sync_all.
> > > 
> > > Thanks!
> > > 
> > > Mathieu
> > > 
> > >>
> > >> Regards,
> > >> Avik
> > >>
> > >> _______________________________________________
> > >> ltt-dev mailing list
> > >> ltt-dev at lists.casi.polymtl.ca
> > >> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
> > >>
> > > 
> > 
> 
> -- 
> Mathieu Desnoyers
> Operating System Efficiency R&D Consultant
> EfficiOS Inc.
> http://www.efficios.com
> 
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-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com