Re: [lttng-dev] Can lttng support kernel function tracer
Hi Zhenyu, If I understandd your question correctly, I can think of two ways to trace an arbitrary kernel function. First, you can hook the tracer on a dynamic probe[1] using something like this: lttng enable-event customEventName -k --probe kernelFunctionName. You can also hook the tracer on both entry and exit of a function using --function instead of --probe. To list your kernel symbols use cat /proc/kallsyms Second, you can create custom kernel tracepoints and compile them in you kernel. Have a look at the online documentation [2]. Don't hesitate to explain further if this doesn't answer your question. Cheers! Francis [1] http://git.lttng.org/?p=lttng-tools.git;a=blob;f=doc/quickstart.txt;h=018c27b2b939ef7cd075255fd01bcfd8b2b21b1e;hb=HEAD#l93 [2] http://lttng.org/docs/#doc-instrumenting-linux-kernel-itself On Thu, Feb 12, 2015 at 7:49 PM, zhenyu.ren zhenyu@aliyun.com wrote: Hi, It's well known that lttng can make use of kernel tracepoints to do block tracing ,system call tracing etc.Is it possible that lttng can produce anything like kernel function tracer does? Thanks zhenyu.ren ___ lttng-dev mailing list lttng-dev@lists.lttng.org http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev ___ lttng-dev mailing list lttng-dev@lists.lttng.org http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
Re: [lttng-dev] Babel trace is throwing error while trying with -i lttng-live option
On Mon, Feb 16, 2015 at 5:33 AM, Ranganadh Kanitmahanti ranganadh1...@yahoo.com wrote: hi, We are using babeltrace 1.2.4 and LTTng Trace Control 2.5.3. Continously giving babeltrace is throwing this error. Sorry about previous conversation. I am actually getting this reading a snapshot session . I have given continously babeltrace and path to read the traces . Then I am getting this error. We see below mentioned error while reading out traces using babeltrace… Okay, so live is not involved at all here? Would it be possible to share the trace? Also, can you provide the commands issued to capture this trace? Thanks, Jérémie [error] Unexpected end of packet. Either the trace data stream is corrupted or metadata description does not match data layout. [error] Reading event failed. Error printing trace. Thanks Regards, K.V.Ranganadh. On Monday, 16 February 2015 2:26 PM, Ranganadh Kanitmahanti ranganadh1...@yahoo.com wrote: Hi, We are using BabelTrace Trace Viewer and Converter 1.2.4 Thanks Regards, K.V.Ranganadh. On Friday, 13 February 2015 8:19 PM, Jérémie Galarneau jeremie.galarn...@efficios.com wrote: On Fri, Feb 13, 2015 at 12:47 AM, Ranganadh Kanitmahanti ranganadh1...@yahoo.com wrote: Hi, [error] Unexpected end of packet. Either the trace data stream is corrupted or metadata description does not match data layout. [error] Reading event failed. Error printing trace. Can any body tell about this significance. I have seen a similar bug resolved Bug #686: stream parser should have a clearer error message when encountering cross-packet fields - Babeltrace - LTTng bugs repository https://bugs.lttng.org/issues/686 Can anybody tell in which version the fix was released. The fix only clarifies the error message. The corrupted stream probably can't be handled by Babeltrace anymore at that point. To answer your question, that fix was introduced in v1.1.2 and is part of all v1.2.x releases. Can you give us more information to reproduce the problem? Which version of LTTng-Tools and Babeltrace are you using? Thanks, Jérémie Bug #686: stream parser should have a clearer error message when encountering cross-packet fields -... https://bugs.lttng.org/issues/686 Redmine View on bugs.lttng.org https://bugs.lttng.org/issues/686 Preview by Yahoo ___ lttng-dev mailing list lttng-dev@lists.lttng.org http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev -- Jérémie Galarneau EfficiOS Inc. http://www.efficios.com -- Jérémie Galarneau EfficiOS Inc. http://www.efficios.com ___ lttng-dev mailing list lttng-dev@lists.lttng.org http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
Re: [lttng-dev] Babel trace is throwing error while trying with -i lttng-live option
hi,We are using babeltrace 1.2.4 and LTTng Trace Control 2.5.3. Continously giving babeltrace is throwing this error. Sorry about previous conversation. I am actually getting this reading a snapshot session . I have given continously babeltrace and path to read the traces . Then I am getting this error.We see below mentioned error while reading out traces using babeltrace… [error] Unexpected end of packet. Either the trace data stream is corrupted or metadata description does not match data layout. [error] Reading event failed. Error printing trace. Thanks Regards,K.V.Ranganadh. On Monday, 16 February 2015 2:26 PM, Ranganadh Kanitmahanti ranganadh1...@yahoo.com wrote: Hi, We are using BabelTrace Trace Viewer and Converter 1.2.4 Thanks Regards,K.V.Ranganadh. On Friday, 13 February 2015 8:19 PM, Jérémie Galarneau jeremie.galarn...@efficios.com wrote: On Fri, Feb 13, 2015 at 12:47 AM, Ranganadh Kanitmahanti ranganadh1...@yahoo.com wrote: Hi, [error] Unexpected end of packet. Either the trace data stream is corrupted or metadata description does not match data layout.[error] Reading event failed.Error printing trace. Can any body tell about this significance. I have seen a similar bug resolved Bug #686: stream parser should have a clearer error message when encountering cross-packet fields - Babeltrace - LTTng bugs repositoryCan anybody tell in which version the fix was released. The fix only clarifies the error message. The corrupted stream probably can't be handled by Babeltrace anymore at that point. To answer your question, that fix was introduced in v1.1.2 and is part of all v1.2.x releases. Can you give us more information to reproduce the problem? Which version of LTTng-Tools and Babeltrace are you using? Thanks,Jérémie | | | | | | | | | Bug #686: stream parser should have a clearer error message when encountering cross-packet fields -...Redmine | | | | View on bugs.lttng.org | Preview by Yahoo | | | | | ___ lttng-dev mailing list lttng-dev@lists.lttng.org http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev -- Jérémie Galarneau EfficiOS Inc. http://www.efficios.com ___ lttng-dev mailing list lttng-dev@lists.lttng.org http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
Re: [lttng-dev] Babel trace is throwing error while trying with -i lttng-live option
Hi, We are using BabelTrace Trace Viewer and Converter 1.2.4 Thanks Regards,K.V.Ranganadh. On Friday, 13 February 2015 8:19 PM, Jérémie Galarneau jeremie.galarn...@efficios.com wrote: On Fri, Feb 13, 2015 at 12:47 AM, Ranganadh Kanitmahanti ranganadh1...@yahoo.com wrote: Hi, [error] Unexpected end of packet. Either the trace data stream is corrupted or metadata description does not match data layout.[error] Reading event failed.Error printing trace. Can any body tell about this significance. I have seen a similar bug resolved Bug #686: stream parser should have a clearer error message when encountering cross-packet fields - Babeltrace - LTTng bugs repositoryCan anybody tell in which version the fix was released. The fix only clarifies the error message. The corrupted stream probably can't be handled by Babeltrace anymore at that point. To answer your question, that fix was introduced in v1.1.2 and is part of all v1.2.x releases. Can you give us more information to reproduce the problem? Which version of LTTng-Tools and Babeltrace are you using? Thanks,Jérémie | | | | | | | | | Bug #686: stream parser should have a clearer error message when encountering cross-packet fields -...Redmine | | | | View on bugs.lttng.org | Preview by Yahoo | | | | | ___ lttng-dev mailing list lttng-dev@lists.lttng.org http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev -- Jérémie Galarneau EfficiOS Inc. http://www.efficios.com ___ lttng-dev mailing list lttng-dev@lists.lttng.org http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
