[ltt-dev] no metadata tracefile

Mathieu Desnoyers compudj at krystal.dyndns.org
Thu Sep 22 09:36:17 EDT 2011 

* Ji Zhai (Ji.Zhai at ca.flextronics.com) wrote:
> Hi Mathieu,
> 
> I'd like to know if you have had time to review my question. If
> possible, can you please give me a guide/direction to debug this
> issure?

Hi Ji,

Sorry, I am pretty busy on UST 2.0 these days.

About your question you might want to try adding "printf" statements
within marker.c in UST, and also try compiling UST with -DUST_DEBUG=1 so
enable debugging output. I fear there is a linker issue on your system,
but unfortunately I don't have access to your setup.

Try comparing the outputs of a simple test program in your powerpc
target setup, in a native host x86 setup, and in a native host x86_64
setup. This way you should be able to identify what is missing.

Best regards,

Mathieu

> 
> For UST-0.15, the epoll must be enabled?
> 
> Where I can get UST 2.0 to try?
> 
> Thanks!
> 
> Regards,
> 
> Ji
> 
> -----Original Message-----
> From: Ji Zhai [mailto:Ji.Zhai at ca.flextronics.com] 
> Sent: Monday, September 19, 2011 11:19 AM
> To: Mathieu Desnoyers
> Cc: ltt-dev at lists.casi.polymtl.ca
> Subject: Re: [ltt-dev] no metadata tracefile
> 
> Hi Mathieu,
> 
> The results for ldd foo:
> root at mcb00-main-aaillax:/home/mvpapp/LTTng# ldd foo
>         linux-vdso32.so.1 =>  (0x00100000)
>         libust.so.0 => /usr/local/lib/libust.so.0 (0x0ff9a000)
>         libc.so.6 => /lib/libc.so.6 (0x0fe34000)
>         libpthread.so.0 => /lib/libpthread.so.0 (0x0fdfc000)
>         librt.so.1 => /lib/librt.so.1 (0x0fdd4000)
>         liburcu-bp.so.1 => /usr/local/lib/liburcu-bp.so.1 (0x0fdae000)
>         /lib/ld.so.1 (0x48000000)
>         liburcu-cds.so.1 => /usr/local/lib/liburcu-cds.so.1 (0x0fd8b000)
> 
> The libust is in /usr/local/lib
> 
> Yes, libust.so is a linker script:
> 
> root at mcb00-main-aaillax:/usr/local/lib# file libust.so
> libust.so: ASCII C program text
> 
> root at mcb00-main-aaillax:/usr/local/lib# cat libust.so
> /* GNU ld script
>    Use the shared library, but the link with initializer too */
> OUTPUT_FORMAT(elf32-powerpc)
> GROUP ( libust.so.0 libust-initializer.o )
> 
> Thanks!
> 
> Ji
> 
> -----Original Message-----
> From: pdumas9 at sympatico.ca [mailto:pdumas9 at sympatico.ca] On Behalf Of Mathieu Desnoyers
> Sent: Monday, September 19, 2011 11:02 AM
> To: Ji Zhai
> Cc: Alexandre Montplaisir; ltt-dev at lists.casi.polymtl.ca
> Subject: Re: [ltt-dev] no metadata tracefile
> 
> * Ji Zhai (Ji.Zhai at ca.flextronics.com) wrote:
> > Hi Mathieu,
> > 
> > Thanks for your help!
> > I use the following way to build my application:
> > gcc -o foo -lust foo.c
> 
> OK. if you run
> 
> ldd foo
> 
> Where does it find its libust ?
> 
> Can you check the content of the libust .so file ? It is supposed to be
> a linker script rather than a .so per se. Can you give us the result of
> "file" and the first lines of the text output of this file ?
> 
> I suspect the build might have installed the .so binary object directly
> without taking into account that it must do this linker trickery.
> 
> By the way, these hacks are going away in UST 2.0.
> 
> Thanks,
> 
> Mathieu
> 
> > 
> > Compiler/linker information:
> > gcc version 4.2.4
> > GNU ld (Linux/GNU Binutils) 2.18.50.0.7.20080502
> > ld.so.1 (GLIBC_2.3)
> > glibc-extra-nss - 2.6.1-r35.0.1
> > glibc-utils - 2.6.1-r35.0.1
> > 
> > Linux kernel: 2.6.31.12
> > 
> > I used 
> > CFLAGS="-m32 -g -O2" ./configure
> > make
> > make install
> > ldconfig
> > to force 32-bit build of userspace-rcu-0.6.4 and ust-0.15.
> > 
> > Thanks!
> > 
> > Ji
> > 
> > -----Original Message-----
> > From: pdumas9 at sympatico.ca [mailto:pdumas9 at sympatico.ca] On Behalf Of Mathieu Desnoyers
> > Sent: Sunday, September 18, 2011 6:23 PM
> > To: Ji Zhai
> > Cc: Alexandre Montplaisir; ltt-dev at lists.casi.polymtl.ca
> > Subject: Re: [ltt-dev] no metadata tracefile
> > 
> > * Ji Zhai (Ji.Zhai at ca.flextronics.com) wrote:
> > > Hi Mathieu,
> > > 
> > > After adding that sleep(5) and even sleep(10), I got some different logs (checked by using hexdump). However, I still got the following error by using the LTTV:
> > > 
> > > ** ERROR **: Undescribed event 1 in channel ust
> > > Aborting...
> > > Lttv: line 15: 26701 Aborted       $0.real $*
> > > 
> > > I have attached the tarball of the usttrace output with debug information.
> > > I am not sure the error came from UST or LTTV. Can you please take a look? Thanks!
> > 
> > Hi Zhai,
> > 
> > The metadata file in the trace you sent is unpopulated. What I mean by
> > this is that the file exists, a 4kB buffer with appropriate header is
> > there, but the metadata that describes the mapping between the markers
> > and their ID/format is missing. This therefore points to a linker
> > problem that causes marker.c to be unable to list the markers present in
> > the application. UST 0.x does require that you link your application
> > with libust-initializer.o in addition to libust. How did you build/link
> > your applications ? And what versions of compiler/linker do you use ?
> > 
> > Thanks,
> > 
> > Mathieu
> > 
> > 
> > > 
> > > Regards,
> > > 
> > > Ji
> > > -----Original Message-----
> > > From: pdumas9 at sympatico.ca [mailto:pdumas9 at sympatico.ca] On Behalf Of Mathieu Desnoyers
> > > Sent: Thursday, September 15, 2011 12:21 PM
> > > To: Ji Zhai
> > > Cc: Alexandre Montplaisir; ltt-dev at lists.casi.polymtl.ca
> > > Subject: Re: [ltt-dev] no metadata tracefile
> > > 
> > > * Ji Zhai (Ji.Zhai at ca.flextronics.com) wrote:
> > > > Hi Alexandre,
> > > > 
> > > > Thanks for your reply!
> > > > According to your suggestions, I did the followings:
> > > > 1. I cleaned all related libs in /usr/local/lib and /usr/lib
> > > > 2. Built/installed userspace-rcu-0.6.4
> > > > 3. Built/installed UST-0.15 with debug enable
> > > > 4. gcc -o foo lust foo.c
> > > > 
> > > >    The foo.c are:
> > > > 
> > > >    #include <ust/marker.h>
> > > > 
> > > >    int main(int argc, char **argv)
> > > >    {
> > > >    int v;
> > > >    char *st;
> > > > 
> > > >    /* ... set values of v and st ... */
> > > >    v = 110;
> > > >    st = "hello, UST";
> > > >    /* a marker: */
> > > >    trace_mark(ust, myevent, "firstarg %d secondarg %s", v, st);
> > > > 
> > > >    /* a marker without arguments: */
> > > >    trace_mark(ust, myotherevent, MARK_NOARGS);
> > > 
> > > Add a sleep(5) here, it will work.
> > > 
> > > This is a fundamental design bug in UST 0.x that we are fixing in UST
> > > 2.0. Short-lived applications don't let enough time for the consumer to
> > > hook on them, and there is no rendez-vous point anywhere. See the
> > > following comment in UST 0.15 sources:
> > > 
> > > tests/runtests:
> > > 
> > > # FIXME We disable the exit-fast test for the release. This is a known
> > > # problem with the current UST design that we will be working on fixing
> > > # in the upcoming rework for integration with the lttng-tools. We don't
> > > # want to flood testers with known issues, hence the choice to disable
> > > # the test.
> > > #simple_harness_run exit-fast/exit-fast.sh
> > > 
> > > Best regards,
> > > 
> > > Mathieu
> > > 
> > > > 
> > > >    return 0;
> > > >   }
> > > > 
> > > > 5. usttrace ./foo
> > > > 6. I got the log files in /home/root/.usttraces.
> > > > 7. I used LTTV(0.12.36) to review the results:
> > > > 
> > > >    lttv -m textDump -t mcb00-main-aaillax-20110914130558687771830
> > > > 
> > > > ** (process:20623): WARNING **: Trace /nas/jizhai/LTTng/mytrace/mcb00-main-aaillax-20110914130558687771830 has no metadata tracefile
> > > > 
> > > > ** (process:20623): CRITICAL **: cannot open trace mcb00-main-aaillax-20110914130558687771830
> > > > /home/jizhai/MyLocal/LTTng/bin/lttv: line 15: 20623 Segmentation fault      $0.real $*
> > > > 
> > > > I have attached the tar ball (foo_ust.tar.gz) for the log files. Please see the attachment.
> > > > 
> > > > My co-worker did same test on his side and sent an email for help to the mailing list:
> > > > 
> > > > http://lists.casi.polymtl.ca/pipermail/ltt-dev/2011-September/005135.html
> > > > 
> > > > In his email, there are some debug information done by him.
> > > > 
> > > > I am looking forward to get your further help! Thanks!
> > > > 
> > > > Regards,
> > > > 
> > > > Ji
> > > > 
> > > > 
> > > > -----Original Message-----
> > > > From: Alexandre Montplaisir [mailto:alexandre.montplaisir at polymtl.ca]
> > > > Sent: Tuesday, September 13, 2011 4:03 PM
> > > > To: Ji Zhai
> > > > Cc: ltt-dev at lists.casi.polymtl.ca
> > > > Subject: Re: [ltt-dev] no metadata tracefile
> > > > 
> > > > On 11-09-13 03:22 PM, Ji Zhai wrote:
> > > > > Hi Mathieu,
> > > > >
> > > > > Thanks for your reply!
> > > > > I have tried many combinations, for example, userspace-rcu-0.6.4 and
> > > > > ust-0.15, but still got the same kind of errors--no metadata trace
> > > > > tracefile.
> > > > > Any idea? Thanks again!
> > > > >
> > > > > Regards,
> > > > >
> > > > > Ji
> > > > 
> > > > Hi Ji Zhai,
> > > > 
> > > > Can you take a really small UST trace (a couple MB's) and upload it
> > > > somewhere?
> > > > 
> > > > Also make sure you are really using the latest versions (urcu 0.6.4, UST
> > > > 0.15 and LTTV 0.12.38). Sometimes old versions are still in the PATH
> > > > even if new versions got installed afterwards. On most distros, stuff in
> > > > /usr/local has priority over stuff in /usr.
> > > > 
> > > > 
> > > > Cheers,
> > > > 
> > > > --
> > > > Alexandre Montplaisir
> > > > DORSAL lab,
> > > > École Polytechnique de Montréal
> > > > 
> > > > 
> > > >  
> > > > Legal Disclaimer:
> > > > The information contained in this message may be privileged and confidential. It is intended to be read only by the individual or entity to whom it is addressed or by their designee. If the reader of this message is not the intended recipient, you are on notice that any distribution of this message, in any form, is strictly prohibited. If you have received this message in error, please immediately notify the sender and delete or destroy any copy of this message
> > > > 
> > > 
> > > 
> > > > _______________________________________________
> > > > 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
> > 
> > 
> > 
> > -- 
> > Mathieu Desnoyers
> > Operating System Efficiency R&D Consultant
> > EfficiOS Inc.
> > http://www.efficios.com
> > 
> 
> -- 
> Mathieu Desnoyers
> Operating System Efficiency R&D Consultant
> EfficiOS Inc.
> http://www.efficios.com
> 
> _______________________________________________
> 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

More information about the lttng-dev mailing list