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Bug #1173

closed

yocto 2.6.1(pre-release) + lttng no kernel logging?

Added by Robert Berger over 5 years ago. Updated over 5 years ago.

Status:
Resolved
Priority:
Normal
Assignee:
-
Target version:
-
Start date:
01/22/2019
Due date:
% Done:

0%

Estimated time:

Description

hardware: i.mx6 quad (Arm v7)

components used:

poky/branch: https://github.com/RobertBerger/poky/tree/2019-01-16-thud-2.6.1-pre-release

layer, which adds 4.19.13 kernel + new lttng components:

https://github.com/RobertBerger/meta-mainline/tree/thud-training-v4.19.x/multi-v7-ml

kernel:

target# uname -a
Linux multi-v7-ml 4.19.13-custom-ml-debug #1 SMP Wed Jan 16 20:05:50 UTC 2019 armv7l armv7l armv7l GNU/Linux

target# gcc --version
gcc (GCC) 8.2.0
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

host# bitbake-layers show-recipes | grep -A1 lttng
lttng-modules:
  multi-v7-ml          2.10.8
--
lttng-tools:
  multi-v7-ml          2.10.5
--
lttng-ust:
  multi-v7-ml          2:2.10.2

--------------------------------------
Session on serial console (so we can see kernel complaints as well) on target:

root@multi-v7-ml:/# export SESSION="test_session" 
root@multi-v7-ml:/# lttng create ${SESSION}
Spawning a session daemon
[   81.444493] lttng_kretprobes: loading out-of-tree module taints kernel.
[   81.451767] lttng_kretprobes: section 4 reloc 5 sym 'strlen': relocation 28 out of range (0xbf0700a0 -> 0xc10a761c)
Session test_session created.
Traces will be written in /home/root/lttng-traces/test_session-20190122-114319
root@multi-v7-ml:/# lsmod
Module                  Size  Used by
rtc_da9063             16384  0
da9062_core            16384  0
rtc_snvs               16384  1
root@multi-v7-ml:/# lttng list
Available tracing sessions:
  1) test_session (/home/root/lttng-traces/test_session-20190122-114319) [inactive]
    Trace path: /home/root/lttng-traces/test_session-20190122-114319

Use lttng list <session_name> for more details
root@multi-v7-ml:/# lttng enable-event --kernel sched_switch,sched_process_fork
[  150.804796] lttng_kretprobes: section 4 reloc 5 sym 'strlen': relocation 28 out of range (0xbf0770a0 -> 0xc10a761c)
Error: Event sched_switch: Kernel tracer not available (channel channel0, session test_session)
[  150.971757] lttng_kretprobes: section 4 reloc 5 sym 'strlen': relocation 28 out of range (0xbf07e0a0 -> 0xc10a761c)
Error: Event sched_process_fork: Kernel tracer not available (channel channel0, session test_session)

Kernel tracer nor available - so I guess there is no point to try more stuff here.

What would you suggest?

root@multi-v7-ml:/# lttng list ${SESSION}
Tracing session test_session: [inactive]
    Trace path: /home/root/lttng-traces/test_session-20190122-114319

root@multi-v7-ml:/# lttng start
Error: No channel found in the session

Am I doing something wrong or do I need some kernel/lttng_modules fixes?

BTW I tried first with whatever comes with my Yocto 2.6.1 pre-release and then upgraded to the latest and greatest lttng I could find on openembedded-core (master).


Files

config (190 KB) config kernel config of "unhappy" kernel Robert Berger, 01/22/2019 10:28 AM
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