[lttng-dev] Best way to analyze CTF files

Christian Babeux christian.babeux at efficios.com
Fri Oct 17 20:13:22 EDT 2014


Hi Sebastien,

A simple Python script using the Babeltrace bindings would probably do
the job here. See [1] for an example using the bindings.

Thanks,

Christian

[1] - https://lttng.org/docs/#doc-viewing-and-analyzing-your-traces

On Fri, Oct 17, 2014 at 6:23 PM, Boisvert, Sebastien <boisvert at anl.gov> wrote:
> Bonjour,
>
> First, thank you for LTTng-UST. This is very useful and convenient.
>
> I just got started today using LTTng (LTTng-UST) for tracing a HPC application
> that I am working on (I am a postdoc). I am impressed by how easy LTTng is to use it.
>
> In my system, an actor message is represented by a pair
> <message_actor_source, message_number>.
>
> I want to list all messages that have a high delivery time (message:actor_receive - message:actor_send).
>
> I am doing this to get the messages of one actor (actor 1000019):
>
> [boisvert at bigmem biosal]$ babeltrace ~/lttng-traces/auto-20141017-181240|grep "message_source_actor = 1000019"  > actor_1000019
>
> Then, I can look at one message with (message <1000019, 14>):
>
> [boisvert at bigmem biosal]$ grep "message_number = 14," actor_1000019
> [18:12:43.647017211] (+0.000005110) bigmem.knoxville.kbase.us message:actor_send: { cpu_id = 30 }, { message_number = 14, message_action = 31592, message_count = 8, message_source_actor = 1000019, message_destination_actor = 1000059, message_source_node = -1, message_destination_node = -1 }
> [18:12:43.647025249] (+0.000002860) bigmem.knoxville.kbase.us message:actor_receive: { cpu_id = 49 }, { message_number = 14, message_action = 31592, message_count = 8, message_source_actor = 1000019, message_destination_actor = 1000059, message_source_node = 3, message_destination_node = 3 }
>
> If I substract the times:
>
> irb(main):003:0> (43.647025249-43.647017211)*10**9
> => 8038.00000426236
>
> This message (<1000019, 14>) required 8038 ns for the delivery. This one is fine.
>
>
> So basically my question is:
>
> Is there an easy way to analyze these tracepoint files ?
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