Thanks Guys, that was the issue, I appreciate your help
-----Original Message-----
From: lttng-dev [mailto:[email protected]] On Behalf Of
[email protected]
Sent: 28 September 2018 17:00
To: [email protected]
Subject: [EXTERNAL] lttng-dev Digest, Vol 125, Issue 18
Send lttng-dev mailing list submissions to
[email protected]
To subscribe or unsubscribe via the World Wide Web, visit
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
or, via email, send a message with subject or body 'help' to
[email protected]
You can reach the person managing the list at
[email protected]
When replying, please edit your Subject line so it is more specific
than "Re: Contents of lttng-dev digest..."
Today's Topics:
1. User Space Tracing (John O'Sullivan)
2. Re: User Space Tracing (Philippe Proulx)
3. Re: User Space Tracing (Mathieu Desnoyers)
----------------------------------------------------------------------
Message: 1
Date: Thu, 27 Sep 2018 16:13:37 +0000
From: John O'Sullivan <[email protected]>
To: "[email protected]" <[email protected]>
Subject: [lttng-dev] User Space Tracing
Message-ID: <[email protected]>
Content-Type: text/plain; charset="iso-8859-1"
I am really struggling trying to get user space tracing working predictably and
consistently and would appreciate some help.
I created a trace event called
kvm_server:new_connection_tracepoint (see attached), I then use lttng-gen-tp to
generate the .c and .h files which I link to the program and call with
tracepoint(kvm_server, new_connection_tracepoint, .................)
This appears predictably in my traces
However if I call my second tracepoint (see attached)
tracepoint(resolution_management, resolution_management_tracepoint,.......)
It never appears in any of the traces
I can see no significant difference between the two definitions.
I then created a third trace definition called simple_example (see attached)
tracepoint(simple_example, simple_example_tracepoint, .....)
This again appears in the trace
I start the tracing using
lttng enable-event -u -a # enable user-space tracing
I then use babel trace to dump the trace,
'kvm_server' and 'simple_example' appear in the trace, resolution_management
does not.
Any idea why the resolution_management tracepoint does not appear in any traces
or is there some way of debugging the tracecall macro itself?
regards
John
________________________________
This email and any files transmitted with it are confidential and are intended
for the sole use of the individual to whom they are addressed. Black Box
Corporation reserves the right to scan all e-mail traffic for restricted
content and to monitor all e-mail in general. If you are not the intended
recipient or you have received this email in error, any use, dissemination or
forwarding of this email is strictly prohibited. If you have received this
email in error, please notify the sender by replying to this email.
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<https://lists.lttng.org/pipermail/lttng-dev/attachments/20180927/749d7398/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: connection_management_tp.tp
Type: application/octet-stream
Size: 2100 bytes
Desc: connection_management_tp.tp
URL:
<https://lists.lttng.org/pipermail/lttng-dev/attachments/20180927/749d7398/attachment-0003.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: resolution_management_tp.tp
Type: application/octet-stream
Size: 1568 bytes
Desc: resolution_management_tp.tp
URL:
<https://lists.lttng.org/pipermail/lttng-dev/attachments/20180927/749d7398/attachment-0004.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: simple_trace_tp.tp
Type: application/octet-stream
Size: 798 bytes
Desc: simple_trace_tp.tp
URL:
<https://lists.lttng.org/pipermail/lttng-dev/attachments/20180927/749d7398/attachment-0005.obj>
------------------------------
Message: 2
Date: Thu, 27 Sep 2018 13:51:05 -0400
From: Philippe Proulx <[email protected]>
To: [email protected]
Cc: [email protected]
Subject: Re: [lttng-dev] User Space Tracing
Message-ID:
<cab4xu_1zofu02ia_xxp0lzu2u+r_rqltq-eadxol1z66kbb...@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
In `resolution_management_tp.tp`, can you try using the exact same
`TP_ARGS` content for both `TRACEPOINT_EVENT_INSTANCE` (also matching
the `TP_ARGS` content of `TRACEPOINT_EVENT_CLASS`)? It's the only
difference I can see.
Philippe Proulx
Philippe Proulx
On Thu, Sep 27, 2018 at 12:15 PM John O'Sullivan
<[email protected]> wrote:
>
> I am really struggling trying to get user space tracing working predictably
> and consistently and would appreciate some help.
>
>
> I created a trace event called
>
> kvm_server:new_connection_tracepoint (see attached), I then use lttng-gen-tp
> to generate the .c and .h files which I link to the program and call with
>
> tracepoint(kvm_server, new_connection_tracepoint, .................)
>
> This appears predictably in my traces
>
> However if I call my second tracepoint (see attached)
>
> tracepoint(resolution_management, resolution_management_tracepoint,.......)
>
> It never appears in any of the traces
>
> I can see no significant difference between the two definitions.
>
>
> I then created a third trace definition called simple_example (see attached)
>
> tracepoint(simple_example, simple_example_tracepoint, .....)
>
> This again appears in the trace
>
>
> I start the tracing using
>
> lttng enable-event -u -a # enable user-space tracing
>
> I then use babel trace to dump the trace,
>
>
> 'kvm_server' and 'simple_example' appear in the trace, resolution_management
> does not.
>
>
>
> Any idea why the resolution_management tracepoint does not appear in any
> traces or is there some way of debugging the tracecall macro itself?
>
>
> regards
>
> John
>
>
> ________________________________
>
> This email and any files transmitted with it are confidential and are
> intended for the sole use of the individual to whom they are addressed. Black
> Box Corporation reserves the right to scan all e-mail traffic for restricted
> content and to monitor all e-mail in general. If you are not the intended
> recipient or you have received this email in error, any use, dissemination or
> forwarding of this email is strictly prohibited. If you have received this
> email in error, please notify the sender by replying to this email.
> _______________________________________________
> lttng-dev mailing list
> [email protected]
> https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
------------------------------
Message: 3
Date: Thu, 27 Sep 2018 15:32:48 -0400 (EDT)
From: Mathieu Desnoyers <[email protected]>
To: Philippe Proulx <[email protected]>
Cc: John OSullivan <[email protected]>, lttng-dev
<[email protected]>
Subject: Re: [lttng-dev] User Space Tracing
Message-ID:
<[email protected]>
Content-Type: text/plain; charset=utf-8
Good catch Philippe,
I pushed a commit that enforces validation of event class/instance
prototypes (TP_ARGS()) at compile-time.
It is pushed into lttng-ust master as:
commit c75c0422c64f33c0102e1778cecc812c58b700e5
Author: Mathieu Desnoyers <[email protected]>
Date: Thu Sep 27 15:21:16 2018 -0400
Fix: check for event class/instance prototype mismatch
The TP_ARGS() for an event instance belonging to an event class
must have compatible types with the event class TP_ARGS().
Failure to follow this rule leads to a prototype mismatch between the
tracepoint call site and the probe function. A common effect perceived
is that events with prototype mismatch between call site and probe
function are never traced.
Fix this by enforcing a compile-time check of the event instance and
class prototypes, similarly to what is done in LTTng modules.
Signed-off-by: Mathieu Desnoyers <[email protected]>
And cherry-picked into lttng-ust 2.11, 2.10, 2.9 stable branches,
Thanks!
Mathieu
----- On Sep 27, 2018, at 1:51 PM, Philippe Proulx [email protected]
wrote:
> In `resolution_management_tp.tp`, can you try using the exact same
> `TP_ARGS` content for both `TRACEPOINT_EVENT_INSTANCE` (also matching
> the `TP_ARGS` content of `TRACEPOINT_EVENT_CLASS`)? It's the only
> difference I can see.
>
> Philippe Proulx
> Philippe Proulx
>
>
> On Thu, Sep 27, 2018 at 12:15 PM John O'Sullivan
> <[email protected]> wrote:
>>
>> I am really struggling trying to get user space tracing working predictably
>> and
>> consistently and would appreciate some help.
>>
>>
>> I created a trace event called
>>
>> kvm_server:new_connection_tracepoint (see attached), I then use lttng-gen-tp
>> to
>> generate the .c and .h files which I link to the program and call with
>>
>> tracepoint(kvm_server, new_connection_tracepoint, .................)
>>
>> This appears predictably in my traces
>>
>> However if I call my second tracepoint (see attached)
>>
>> tracepoint(resolution_management, resolution_management_tracepoint,.......)
>>
>> It never appears in any of the traces
>>
>> I can see no significant difference between the two definitions.
>>
>>
>> I then created a third trace definition called simple_example (see attached)
>>
>> tracepoint(simple_example, simple_example_tracepoint, .....)
>>
>> This again appears in the trace
>>
>>
>> I start the tracing using
>>
>> lttng enable-event -u -a # enable user-space tracing
>>
>> I then use babel trace to dump the trace,
>>
>>
>> 'kvm_server' and 'simple_example' appear in the trace, resolution_management
>> does not.
>>
>>
>>
>> Any idea why the resolution_management tracepoint does not appear in any
>> traces
>> or is there some way of debugging the tracecall macro itself?
>>
>>
>> regards
>>
>> John
>>
>>
>> ________________________________
>>
>> This email and any files transmitted with it are confidential and are
>> intended
>> for the sole use of the individual to whom they are addressed. Black Box
>> Corporation reserves the right to scan all e-mail traffic for restricted
>> content and to monitor all e-mail in general. If you are not the intended
>> recipient or you have received this email in error, any use, dissemination or
>> forwarding of this email is strictly prohibited. If you have received this
>> email in error, please notify the sender by replying to this email.
>> _______________________________________________
>> lttng-dev mailing list
>> [email protected]
>> https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
> _______________________________________________
> lttng-dev mailing list
> [email protected]
> https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
------------------------------
Subject: Digest Footer
_______________________________________________
lttng-dev mailing list
[email protected]
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
------------------------------
End of lttng-dev Digest, Vol 125, Issue 18
******************************************
_______________________________________________
lttng-dev mailing list
[email protected]
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
