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From: Jonathan Rajotte-Julien via lttng-dev <lttng-dev@lists.lttng.org>
To: Abhinav Ranjan <abhi.abhinav240@gmail.com>
Cc: lttng-dev@lists.lttng.org
Subject: Re: Need Help In trace generation for malloc(), free() calls etc
Date: Wed, 13 May 2020 11:33:12 -0400	[thread overview]
Message-ID: <20200513153312.GA2381108@joraj-alpa> (raw)
In-Reply-To: <CAPC3erkxTh9dSgahym7xsCjJXOV3D+kto-=UB-ApjSUOWYZVeA@mail.gmail.com>

Hi Abhinav,

Please refrain from using screenshots when pastebin could be used (code,
commands, etc).

On Wed, May 13, 2020 at 10:29:22AM +0530, Abhinav Ranjan via lttng-dev wrote:
>   Hello Sir,
> I am Abhinav from India.
> *Kindly Ignore the previous email.*
> Actually I am very new to the Embedded System Engineering profession. In
> fact I have been asked to do an independent project to instrumenting a c
> application using  LLTng concept to find/trace calls to malloc(), free()
> calls. In fact i tried capturing the same as below steps but didn't
> understand why after using LD_PRELOAD also malloc() and free() calls were
> not traced. I am not sure whether my app was correct!!
> 
>  I followed the steps provided to create executable using -lltng-ust -ldl
> 2.I executed it as: LD_PRELOAD=liblttng-ust-libc-wrapper.so ./executable
> (initially as ./exe arg))
> 3. Then I followed commands to create , capture the events. and destroyed
> it.

Based on the screenshot "creation_trace.PNG", it seems that you enable only the
event you defined (malloc_trace_investigation). Keep in mind that the libc
wrapper defines its own tracepoints and tracepoint providers.

It the case of the libc wrapper the tracepoint providers available are:
lttng_ust_libc and lttng_ust_pthread

Both have multiple tracepoints defined under them.

Hence what you want for you experiment is something like this:

    lttng enable-event -u malloc_trace:investigation
    lttng enable-event -u 'lttng_ust_libc:*'

Keep in mind that you can list the events available for a currently running app
using:

   lttng list -u


The app must be running for the listing work.

Cheers.

WARNING: multiple messages have this Message-ID
From: Jonathan Rajotte-Julien via lttng-dev <lttng-dev@lists.lttng.org>
To: Abhinav Ranjan <abhi.abhinav240@gmail.com>
Cc: lttng-dev@lists.lttng.org
Subject: Re: [lttng-dev] Need Help In trace generation for malloc(), free() calls etc
Date: Wed, 13 May 2020 11:33:12 -0400	[thread overview]
Message-ID: <20200513153312.GA2381108@joraj-alpa> (raw)
Message-ID: <20200513153312.A_aLo16tZpovLe6hYgVamYNBAZm7SmPCJWBB5TQ2vh4@z> (raw)
In-Reply-To: <CAPC3erkxTh9dSgahym7xsCjJXOV3D+kto-=UB-ApjSUOWYZVeA@mail.gmail.com>

Hi Abhinav,

Please refrain from using screenshots when pastebin could be used (code,
commands, etc).

On Wed, May 13, 2020 at 10:29:22AM +0530, Abhinav Ranjan via lttng-dev wrote:
>   Hello Sir,
> I am Abhinav from India.
> *Kindly Ignore the previous email.*
> Actually I am very new to the Embedded System Engineering profession. In
> fact I have been asked to do an independent project to instrumenting a c
> application using  LLTng concept to find/trace calls to malloc(), free()
> calls. In fact i tried capturing the same as below steps but didn't
> understand why after using LD_PRELOAD also malloc() and free() calls were
> not traced. I am not sure whether my app was correct!!
> 
>  I followed the steps provided to create executable using -lltng-ust -ldl
> 2.I executed it as: LD_PRELOAD=liblttng-ust-libc-wrapper.so ./executable
> (initially as ./exe arg))
> 3. Then I followed commands to create , capture the events. and destroyed
> it.

Based on the screenshot "creation_trace.PNG", it seems that you enable only the
event you defined (malloc_trace_investigation). Keep in mind that the libc
wrapper defines its own tracepoints and tracepoint providers.

It the case of the libc wrapper the tracepoint providers available are:
lttng_ust_libc and lttng_ust_pthread

Both have multiple tracepoints defined under them.

Hence what you want for you experiment is something like this:

    lttng enable-event -u malloc_trace:investigation
    lttng enable-event -u 'lttng_ust_libc:*'

Keep in mind that you can list the events available for a currently running app
using:

   lttng list -u


The app must be running for the listing work.

Cheers.
_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev

       reply	other threads:[~2020-05-13 15:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CAPC3ern8bkAJDnOwoYh2Om44Q2GWAPsh140FW_aPGVkdUmCwkw@mail.gmail.com>
     [not found] ` <CAPC3erkxTh9dSgahym7xsCjJXOV3D+kto-=UB-ApjSUOWYZVeA@mail.gmail.com>
2020-05-13 15:33   ` Jonathan Rajotte-Julien via lttng-dev [this message]
2020-05-13 15:33     ` [lttng-dev] " Jonathan Rajotte-Julien via lttng-dev
     [not found]     ` <CAPC3erkfapoZu_WM=znEyj0ch1YiKeX7-JBiauoLh+Seee0TZA@mail.gmail.com>
2020-05-13 18:04       ` Jonathan Rajotte-Julien via lttng-dev
2020-05-13 18:04         ` [lttng-dev] " Jonathan Rajotte-Julien via lttng-dev
2020-05-14  5:25         ` Abhinav Ranjan via lttng-dev
2020-05-14  5:25           ` [lttng-dev] " Abhinav Ranjan via lttng-dev

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