Thanks Guys, that was the issue, I appreciate your help -----Original Message----- From: lttng-dev [mailto:lttng-dev-boun...@lists.lttng.org] On Behalf Of lttng-dev-requ...@lists.lttng.org Sent: 28 September 2018 17:00 To: lttng-dev@lists.lttng.org Subject: [EXTERNAL] lttng-dev Digest, Vol 125, Issue 18
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Re: User Space Tracing (Mathieu Desnoyers) ---------------------------------------------------------------------- Message: 1 Date: Thu, 27 Sep 2018 16:13:37 +0000 From: John O'Sullivan <john.osulli...@blackbox.com> To: "lttng-dev@lists.lttng.org" <lttng-dev@lists.lttng.org> Subject: [lttng-dev] User Space Tracing Message-ID: <1538064817178.44...@blackbox.com> 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 <eeppelitel...@gmail.com> To: john.osulli...@blackbox.com Cc: lttng-dev@lists.lttng.org 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 <john.osulli...@blackbox.com> 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 > lttng-dev@lists.lttng.org > 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 <mathieu.desnoy...@efficios.com> To: Philippe Proulx <eeppelitel...@gmail.com> Cc: John OSullivan <john.osulli...@blackbox.com>, lttng-dev <lttng-dev@lists.lttng.org> Subject: Re: [lttng-dev] User Space Tracing Message-ID: <1491039245.11707.1538076768518.javamail.zim...@efficios.com> 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 <mathieu.desnoy...@efficios.com> 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 <mathieu.desnoy...@efficios.com> 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 eeppelitel...@gmail.com 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 > <john.osulli...@blackbox.com> 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 >> lttng-dev@lists.lttng.org >> https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev > _______________________________________________ > lttng-dev mailing list > lttng-dev@lists.lttng.org > 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 lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev ------------------------------ End of lttng-dev Digest, Vol 125, Issue 18 ****************************************** _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev