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From: Simon Marchi via lttng-dev <lttng-dev@lists.lttng.org>
To: Dimitri Scheftelowitsch <dimitri.scheftelowitsch@esrlabs.com>,
	lttng-dev@lists.lttng.org
Subject: Re: [lttng-dev] Babeltrace trimmer segfaults on custom trace
Date: Wed, 5 May 2021 09:45:58 -0400	[thread overview]
Message-ID: <555b0ddc-fbad-82d0-c052-27006310a577@polymtl.ca> (raw)
In-Reply-To: <69a2d37a-d60d-deba-02d2-c3084f62b84f@polymtl.ca>

On 2021-05-04 9:57 p.m., Simon Marchi via lttng-dev wrote:
> I tried to see if it would be possible for you
> to just not use packets, but unfortunately I stumbled on what looks like
> a bug in the CTF metadata parser, it hardcodes whether streams classes
> have packets to true:
> 
>   https://github.com/efficios/babeltrace/blob/534d93a8b2ba86f56dfdf6aa7a10911da5f6432c/src/plugins/ctf/common/metadata/ctf-meta-translate.c#L576

Hi Dimitri,

After talking with Philippe (Babeltrace 2's main contributor), this is
not a bug in the CTF metadata parser.  According to [1]:

    If the packet size field is missing, the whole stream only contains a single packet. 

So when if you don't have a packet header/context at all, the trace is
considered to have a single big packet.  That's why the metadata parser
always create streams with packets.

But the suggestion of adding timestamps to your packet is still valid.

Simon

[1] https://diamon.org/ctf/#spec5.2
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  reply	other threads:[~2021-05-05 13:46 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-04 14:21 [lttng-dev] Babeltrace trimmer segfaults on custom trace Dimitri Scheftelowitsch via lttng-dev
2021-05-05  1:57 ` Simon Marchi via lttng-dev
2021-05-05 13:45   ` Simon Marchi via lttng-dev [this message]
2021-05-20  8:34     ` [lttng-dev] [External] " Dimitri Scheftelowitsch via lttng-dev

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