RE: [EXT] Re: [dpdk-users] Unable to see traces from a user defined DPDK Tracepoint

[Jerin Jacob Kollanukkaran <jerinj@marvell.com>]

There is a test app which uses application specific trace points. Please check with same.

Steps:

meson build
ninja -C build
echo "trace_autotest" |  ./build/app/test/dpdk-test  -c 0x3 --trace=.* --no-huge --trace=.*
[main]dell[dpdk.org] $ babeltrace /home/jerin/dpdk-traces/rte-2023-10-29-PM-12-51-21/ | grep app
[12:51:21.746112807] (+0.000003576) app.dpdk.test.tp: { cpu_id = 0x0, name = "dpdk-test" }, { str = "app.dpdk.test.tp" }

Change /home/jerin/dpdk-traces/rte-2023-10-29-PM-12-51-21 as neded.




> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Friday, October 27, 2023 1:41 PM
> To: Sanjit Kumar <sanjit.kumar@aviznetworks.com>
> Cc: users@dpdk.org; utkarshece80587@gmail.com; 4plague@gmail.com; Jerin
> Jacob Kollanukkaran <jerinj@marvell.com>; Sunil Kumar Kori
> <skori@marvell.com>
> Subject: [EXT] Re: [dpdk-users] Unable to see traces from a user defined DPDK
> Tracepoint
> 
> External Email
> 
> ----------------------------------------------------------------------
> Hello,
> 
> Copying trace framework maintainers.
> 
> On Fri, Oct 27, 2023 at 9:48 AM Sanjit Kumar
> <sanjit.kumar@aviznetworks.com> wrote:
> > I am trying to test the usage of the DPDK trace library. I have run into the
> same issue as recounted here -
> https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__mails.dpdk.org_archives_users_2020-
> 2DDecember_005266.html&d=DwIFaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=1DG
> ob4H4rxz6H8uITozGOCa0s5f4wCNtTa4UUKvcsvI&m=8lGjvR2Zzx16oDmIlUa-
> 4sbOVuprWKDQOcr9sq00B8VUgs2UfcWPOKTCeVDXfN49&s=B9Ku1Ax4QxxcQs
> ujPn-YfHCsgjexKNDdycP0OhTWuAw&e=   - where I am able to build and run my
> DPDK application where I have created and registered my custom trace point
> (verified via rte_trace_dump(stdout) which says my traces are 'enabled' - i see
> the right trace buffer size, trace file destination etc). The trace point creation
> and registration are identical to what is mentioned in the program guide using
> RTE_TRACE_POINT in a header file and registering it in my dpdk application via
> RTE_TRACE_POINT_REGISTER macro.
> >
> > What I notice are as follows:
> >
> > 1. The program builds and runs as intended.
> > 2. The trace files are generated in the correct destination directory.
> > 3. On using trace=.*  ----> I see a huge list of traces on viewing the trace file
> with babeltrace - but do not see my custom trace point. I also do not see any
> trace output from my dpdk application if I reuse DPDK library traces ( eg:
> rte_eal_trace_thread_lcore_ready ) instead of defining my own custom traces.
> > 4. On using trace=<regex for traces used in my application> i do not see any
> trace output just used inside my application.
> >
> > I think the above observations suggest that the issue might be in configuring
> my DPDK application to recognize and create trace output properly. However
> the rte_trace_dump output suggests that trace is enabled here.
> >
> > What I would like to know is similar to utkarsh's question:
> > Is there anything I am missing in configuring my application to recognize
> traces? If so can you please point it out?
> 
> I think a hint was posted later, about this topic.
> Did you compile your application tracepoint register code with -
> DALLOW_EXPERIMENTAL_API ?
> 
> If you confirm it solves your issue, we need to enhance the trace framework
> documentation.
> 
> 
> --
> David Marchand