[ltt-dev] Kernel crashes when creating a trace

[Mathieu Desnoyers]

* Ashwin Tanugula (ashwin.tanugula at broadcom.com) wrote:
> Hi Mathieu,
> 
> I am able to generate and view the trace with the latest lttng patchset and ltt-control package.
> 
> patch-2.6.31.6-lttng-0.168 and ltt-control-0.74-12112009
> 
> I didn't even put "return 1;" at the beginning of trace_clock_async_tsc_read, get_trace_clock and put_trace_clock functions.
> 

Great ! Thanks for your help with testing on MIPS32. Do you still get
warnings when you start tracing ?

Mathieu

> However, I will further test this and update you.
> 
> The only thing I needed was to add the following to lttd.c (as my uClibc is missing the splice system call)
> 
> 
> # define SPLICE_F_MOVE                1       /* Move pages instead of copying.  */
> # define SPLICE_F_MORE                4       /* Expect more data.  */
> 
> #include <sys/syscall.h>
> #define splice(...)      syscall(__NR_splice, __VA_ARGS__)
> 
> 
> Thank you very much for all your help.
> 
> 
> Ashwin
> 
> 
> * Ashwin Tanugula (ashwin.tanugula at broadcom.com) wrote:
> > Mathieu,
> > 
> > I made the same changes to the kernel with patch-2.6.31.3-lttng-0.162 
> > and I don't see a kernel crash. (I hope this helps to narrow down the 
> > problem)
> > 
> > However the trace data is not generated.
> > 
> 
> Also try upgrading to the brand new ltt-control 0.74. I just saw that a return value was missing from the __lttctl_set_channel_subbuf_size function in liblttctl. It could also help.
> 
> Thanks,
> 
> Mathieu
> 
> 

-- 
Mathieu Desnoyers
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