On 24 Jun (08:47:21), Thierry Bultel wrote: > Hi, > > I am using lttng (2.4.1), target is ARM Cortex A9; compiler is gcc-4.7.3, > but I have the same issue with gcc-4.8.2 > The kernel is Freescale's 3.0.35-4.1.0 > > > lttng fails to start: > > [root@buildroot ~]# lttng create > Session auto-19700319-135920 created. > Traces will be written in /root/lttng-traces/auto-19700319-135920 > [root@buildroot~]# lttng enable-event --kernel --all > PERROR [5831/5915]: wait: Success (in run_as_clone() at runas.c:243) > Error: Trace directory creation error > Error: Events: Kernel create session failed (channel channel0, session > auto-19700319-135920) > > My analysis show that lttng attempts to create the trace directory, when > "lttng enable-event" is called. > To do so, it uses a slave thread that performs a kind of "mkdir -p" , > that thread is spawned via a call to "clone" > and the father waits for it via "waitpid". > > When the slave returns, waitpid says it is not completed. Added a little > code to shows that the thread > is killed with SIGSEGV at the time it calls "return" > > Changing it to call "exit" instead, makes it a little better, but other > numerous errors come when > calling "lttng start" > > Did anyone encounter such an issue ?
Hrm, tbh I never tried lttng-tools on ARM but if a SIGSEGV is raised you should be able to get a core dump and with gdb we can understand which callsite failed badly. Thanks! David > > Best regards > Thierry Bultel > > > > > _______________________________________________ > lttng-dev mailing list > [email protected] > http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
signature.asc
Description: Digital signature
_______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
