Thanks Mathieu. If I understand correctly, lttng-modules output necessary
information as lttng_statedump_file_descriptor, and it is a part of CTF.
But when babeltrace parse CTF, it does not process those information.
lttng-analyses is post-processing python scripts while babeltrace is realtime C
parser.
If we decide to extend babeltrace to support the filename-fd mapping like iolog
functionality in lttng-analyses, any recommendation?
Regards
Hai
------------------ Original ------------------
From: "Mathieu Desnoyers"<mathieu.desnoy...@efficios.com>;
Date: Tue, Nov 26, 2019 10:47 PM
To: "杨海"<hai.y...@magic-shield.com>;
Cc: "lttng-dev"<lttng-dev@lists.lttng.org>; "Matthew
Khouzam"<matthew.khou...@ericsson.com>; "Geneviève
Bastien"<gbast...@versatic.net>;
Subject: Re: 回复:Re: [lttng-dev] documentation about CTF event payload
Hi,
(adding back lttng-dev in CC for the benefit of others)
Whenever possible, we try to augment the trace data with such additional
information at post-processing, because capturing it at run-time repeatedly ends
up being costly.
The lttng-analyses project contains state tracker which augment the trace data
with mapping from file descriptor to corresponding file names (see
lttnganalyses/linuxautomaton/io.py).
I'm not sure if the Trace Compass project models this mapping between file
descriptors and their
associated file, but if not, it would be an *extremely* useful addition.
lttng-modules already dumps the information needed to create that model:
- lttng_statedump_file_descriptor dumps all existing file descriptors for all
processes,
- a few system calls (open, dup, dup2, dup3, close, clone(see CLONE_FILES
flag), fork,
fcntl(cmd==F_DUPFD)) allow tracking the file descriptor table state changes
during the trace.
Thanks,
Mathieu
----- On Nov 25, 2019, at 7:36 PM, 杨海 <hai.y...@magic-shield.com> wrote:
Hi Mathieu
Thanks for quick response. Here let me give an example. For syscalls open,
LTTng output filename in entry_open and output fd as ret in exit_open. It would
be desired to output both filename and fd so we can correlate them.
I am not sure whether there is a configuration that we can have the richest
output regarding to syscalls.
If not, we can modify lttng-modules to output what we need. Or any other
recommendation?
Regards
Hai
----------
该邮件从移动设备发送
--------------原始邮件--------------
发件人："Mathieu Desnoyers "<mathieu.desnoy...@efficios.com>;
发送时间：2019年11月20日(星期三) 晚上10:32
收件人："杨海" <hai.y...@magic-shield.com>;
抄送："lttng-dev "<lttng-dev@lists.lttng.org>;
主题：Re: [lttng-dev] documentation about CTF event payload
-----------------------------------
For the system call payload documentation, you might want to refer to the
Linux system call
man pages.
For internal kernel tracepoints like sched_switch, there is no documentation of
the meaning of
each field at the moment. This state is the same as the upstream Linux kernel
trace event. You'll
have to figure it out on your own. Documenting each field of the ~500-1000
Linux kernel tracepoints
is no small task.
Thanks,
Mathieu
----- On Nov 19, 2019, at 9:25 PM, 杨海 <hai.y...@magic-shield.com> wrote:
To be more specific, I suppose we can refer to
instrumentation\syscalls\3.10.0-rc7\x86-64-syscalls-3.10.0-rc7 for the payload
format of syscall event. Is it exactly in the CTF syscall event?
Regards
Hai
------------------ Original ------------------
From: "杨海"<hai.y...@magic-shield.com>;
Date: Mon, Nov 18, 2019 09:54 AM
To: "lttng-dev"<lttng-dev@lists.lttng.org>;
Subject: documentation about CTF event payload
Hi
As LTTng generated CTF and babeltrace parse it, we have the output as attached.
We saw events such as sched_switch, but the payload cannot be understood
easily. Where we can find the document to explain the LTTng payload and
parameters?
Regards
Hai
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--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
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