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Bug #232

closed

"No kernel consumer detected" error when starting UST trace with a call to lttng_start_tracing

Added by Raphaël Beamonte over 12 years ago. Updated about 12 years ago.

Status:
Invalid
Priority:
Normal
Assignee:
David Goulet
Target version:
-
Start date:
04/30/2012
Due date:
% Done:

0%

Estimated time:

Description

When starting an UST trace in a small C application, when we call 'lttng_start_tracing' the error "No kernel consumer detected" is thrown (minimal.c:145).
This problem disappear if, during the lttng-sessiond run, a kernel trace was made previously.

The files that are joined to this bug report allows to reproduce the error.
It seems that the bug is located between commits b883c01 and e371dbd.

Files

Download all files
minimal.c (4.27 KB) minimal.c minimal use case Raphaël Beamonte, 04/30/2012 03:36 PM
tracepoint_ust.c (616 Bytes) tracepoint_ust.c UST tracepoint declaration Raphaël Beamonte, 04/30/2012 03:36 PM
ust_xhp.h (1.18 KB) ust_xhp.h UST tracepoint definition Raphaël Beamonte, 04/30/2012 03:36 PM
Makefile (223 Bytes) Makefile Makefile Raphaël Beamonte, 04/30/2012 03:36 PM
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 #1

Updated by Raphaël Beamonte over 12 years ago

The error disappear when the compilation is made with -O1 instead of -O2. It also works with -Os and -O0.

Another way to make it disapear is the add the following loop at first in the main:

volatile int w = 0;
while (w < 1) {
    w++;
}

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 #2

Updated by David Goulet over 12 years ago

  • Assignee set to David Goulet
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 #3

Updated by Raphaël Beamonte over 12 years ago

Is there any news about this bug ?

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 #4

Updated by David Goulet about 12 years ago

  • Status changed from New to Feedback

This is fixed on my side with the latest lttng-tools and UST.

If you still have this problem, please send the session daemon logs with "-vvv --verbose-consumer" and the UST debug output also.

Thanks

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 #5

Updated by David Goulet about 12 years ago

  • Status changed from Feedback to Invalid
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