Re: [i3] Debugging techniques.

[Michael Stapelberg]

Starting i3 with --shmlog-size is a good idea if you’re interested in the
logs, and we even ship a session file for that (so that you can just select
“i3 (with debug log)” in your session manager:
https://github.com/i3/i3/blob/next/i3-with-shmlog.xsession.desktop

As for “-V -d all”, I already mentioned how it might be inconvenient for
users to rotate the log files away. As long as you’re prepared for that, go
ahead :).

On Fri, Oct 30, 2015 at 10:56 PM, Layus  wrote:

> Thank you for the detailed answer.
>
> I think I have sorted it all out.
>
> My use case is an i3 session started with some session manager like gdm or
> kdm (or any other *dm).
> In that setup, the users have little access to the arguments passed to i3.
>
> Let's assume the system uses an i3 build from git@master.
> It should be sufficient to start i3 as "i3 --shmlog-size=2500 -V -d
> all" to get extended logs including the starting phase, and suitable for
> bug reports.
>
> If users are annoyed by the memory usage, they can add 'exec
> --no-startup-id i3-msg shmlog no' to their config.
>
> This way, I enable users to
> 1) access complete logs suitable for debug without needing root access
> 2) disable i3 logging if they do not want it
>
> If it is not an up-to-date git build, they can still use the logs it for
> their own debug purposes.
>
> Do you think the idea of always starting i3 with the
> "--shmlog-size=2500 -V -d all" parameters makes sense ?
>
> --
> Regards,
> Layus
>
>
> On 27/10/15 15:22, Michael Stapelberg wrote:
>
>
>
> On Tue, Oct 27, 2015 at 7:01 AM, Guillaume Maudoux (Layus) <
> layus...@gmail.com> wrote:
>
>> Hello world!
>>
>> I am trying to enable debugging in i3, and I am confused by the number of
>> different options to do this.
>>
>>command line  config option
>> --   -
>> 1 i3 --shmlog-size=X shmlog on|off|toggle|
>>
>
> Note that “shmlog on|off|toggle|” refers to a command, not a config
> directive.
>
> 2  i3 -V ?
>>
>
> Errors (ELOG in the code) are always printed to stdout.
> Verbose log messages (LOG in the code) are printed to stdout if -V is
> enabled. Intended for curious users.
> Debug log messages (DLOG in the code) are printed if -d is enabled.
>
>
>> 3  i3 -d all ?
>> 4  ? debuglog on|off|toggle
>>
>
> 3 and 4 are the same setting. The “all” argument to -d is obsolete, but
> kept for backwards compatibility.
>
> See also https://github.com/i3/i3/issues/1823 for a related discussion.
>
>
>>
>> So my question are:
>>
>> Which one is the recommended way ?
>>
>
> The recommended way is to use an automatically built version from
> http://i3wm.org/docs/repositories.html (or i3-git if your package manager
> knows how to build automatically build software from git) because otherwise
> any of your findings will need to be confirmed again on a more recent
> version.
>
> These versions automatically enable debug logging to shared memory (they
> check whether they were built from a git version that is not a release
> version).
>
>
>> Does `shmlog on` imply  `debuglog on` ?
>>
>
> No.
>
>
>> Does `-d all` imply `-V` ?
>>
>
> No.
>
>
>> What size do you recommend for the shmlog size ?
>>
>
> 25MB (arbitrarily chosen, but proven to be enough for all issues we’ve
> encountered so far).
>
>
>> May I assume that the config options cannot be used to debug issues prior
>> to loading the configuration file (nor issues while loading the
>> configuration file) ?
>>
>
> If you specify them as command-line parameters to i3, they will be active
> before loading the configuration file.
>
>
>> Which of these options provide enough information for a bug report ? Is
>> -V enough ?
>>
>
> Please use -V -d all, as per section 2 of
> http://i3wm.org/docs/debugging.html
>
>
>>
>> It seems that shm logging is better in the sense that it does not
>> increase a log file size, but not as nice as it locks some memory space.
>>
>
> Correct.
>
>
>> What is the reason behind shm logging, instead of the usual logging to
>> file + logrotate ?
>
>
> It’s easier for us to set aside a chunk of memory than to make sure that
> every user of i3 knows about having to logrotate a file away. Anecdotally,
> we’ve had a bunch of users whose hard drive (or RAM, in case of /tmp being
> on tmpfs) filled up because of an ever-growing i3 logfile.
>
> --
> Best regards,
> Michael
>
>
>


-- 
Best regards,
Michael

Re: [i3] Debugging techniques.

[Layus]

Thank you for the detailed answer.

I think I have sorted it all out.

My use case is an i3 session started with some session manager like gdm 
or kdm (or any other *dm).

In that setup, the users have little access to the arguments passed to i3.

Let's assume the system uses an i3 build from git@master.
It should be sufficient to start i3 as "i3 --shmlog-size=2500 -V -d 
all" to get extended logs including the starting phase, and suitable for 
bug reports.


If users are annoyed by the memory usage, they can add 'exec 
--no-startup-id i3-msg shmlog no' to their config.


This way, I enable users to
1) access complete logs suitable for debug without needing root access
2) disable i3 logging if they do not want it

If it is not an up-to-date git build, they can still use the logs it for 
their own debug purposes.


Do you think the idea of always starting i3 with the 
"--shmlog-size=2500 -V -d all" parameters makes sense ?


--
Regards,
Layus

On 27/10/15 15:22, Michael Stapelberg wrote:



On Tue, Oct 27, 2015 at 7:01 AM, Guillaume Maudoux (Layus) 
 wrote:


Hello world!

I am trying to enable debugging in i3, and I am confused by the
number of different options to do this.

   command line  config option
--   -
1 i3 --shmlog-size=X shmlog on|off|toggle|


Note that “shmlog on|off|toggle|” refers to a command, not a 
config directive.


2 i3 -V ?


Errors (ELOG in the code) are always printed to stdout.
Verbose log messages (LOG in the code) are printed to stdout if -V is 
enabled. Intended for curious users.

Debug log messages (DLOG in the code) are printed if -d is enabled.

3 i3 -d all ?
4  ? debuglog on|off|toggle


3 and 4 are the same setting. The “all” argument to -d is obsolete, 
but kept for backwards compatibility.


See also https://github.com/i3/i3/issues/1823 for a related discussion.


So my question are:

Which one is the recommended way ?


The recommended way is to use an automatically built version from 
http://i3wm.org/docs/repositories.html (or i3-git if your package 
manager knows how to build automatically build software from git) 
because otherwise any of your findings will need to be confirmed again 
on a more recent version.


These versions automatically enable debug logging to shared memory 
(they check whether they were built from a git version that is not a 
release version).


Does `shmlog on` imply  `debuglog on` ?


No.

Does `-d all` imply `-V` ?


No.

What size do you recommend for the shmlog size ?


25MB (arbitrarily chosen, but proven to be enough for all issues we’ve 
encountered so far).


May I assume that the config options cannot be used to debug
issues prior to loading the configuration file (nor issues while
loading the configuration file) ?


If you specify them as command-line parameters to i3, they will be 
active before loading the configuration file.


Which of these options provide enough information for a bug report
? Is -V enough ?


Please use -V -d all, as per section 2 of 
http://i3wm.org/docs/debugging.html



It seems that shm logging is better in the sense that it does not
increase a log file size, but not as nice as it locks some memory
space.


Correct.

What is the reason behind shm logging, instead of the usual
logging to file + logrotate ?


It’s easier for us to set aside a chunk of memory than to make sure 
that every user of i3 knows about having to logrotate a file away. 
Anecdotally, we’ve had a bunch of users whose hard drive (or RAM, in 
case of /tmp being on tmpfs) filled up because of an ever-growing i3 
logfile.


--
Best regards,
Michael

Re: [i3] Debugging techniques.

[Michael Stapelberg]

On Tue, Oct 27, 2015 at 7:01 AM, Guillaume Maudoux (Layus) <
layus...@gmail.com> wrote:

> Hello world!
>
> I am trying to enable debugging in i3, and I am confused by the number of
> different options to do this.
>
>command line  config option
> --   -
> 1 i3 --shmlog-size=X shmlog on|off|toggle|
>

Note that “shmlog on|off|toggle|” refers to a command, not a config
directive.

2  i3 -V ?
>

Errors (ELOG in the code) are always printed to stdout.
Verbose log messages (LOG in the code) are printed to stdout if -V is
enabled. Intended for curious users.
Debug log messages (DLOG in the code) are printed if -d is enabled.


> 3  i3 -d all ?
> 4  ? debuglog on|off|toggle
>

3 and 4 are the same setting. The “all” argument to -d is obsolete, but
kept for backwards compatibility.

See also https://github.com/i3/i3/issues/1823 for a related discussion.


>
> So my question are:
>
> Which one is the recommended way ?
>

The recommended way is to use an automatically built version from
http://i3wm.org/docs/repositories.html (or i3-git if your package manager
knows how to build automatically build software from git) because otherwise
any of your findings will need to be confirmed again on a more recent
version.

These versions automatically enable debug logging to shared memory (they
check whether they were built from a git version that is not a release
version).


> Does `shmlog on` imply  `debuglog on` ?
>

No.


> Does `-d all` imply `-V` ?
>

No.


> What size do you recommend for the shmlog size ?
>

25MB (arbitrarily chosen, but proven to be enough for all issues we’ve
encountered so far).


> May I assume that the config options cannot be used to debug issues prior
> to loading the configuration file (nor issues while loading the
> configuration file) ?
>

If you specify them as command-line parameters to i3, they will be active
before loading the configuration file.


> Which of these options provide enough information for a bug report ? Is -V
> enough ?
>

Please use -V -d all, as per section 2 of
http://i3wm.org/docs/debugging.html


>
> It seems that shm logging is better in the sense that it does not increase
> a log file size, but not as nice as it locks some memory space.
>

Correct.


> What is the reason behind shm logging, instead of the usual logging to
> file + logrotate ?


It’s easier for us to set aside a chunk of memory than to make sure that
every user of i3 knows about having to logrotate a file away. Anecdotally,
we’ve had a bunch of users whose hard drive (or RAM, in case of /tmp being
on tmpfs) filled up because of an ever-growing i3 logfile.

-- 
Best regards,
Michael

[i3] Debugging techniques.

[Guillaume Maudoux (Layus)]

Hello world!

I am trying to enable debugging in i3, and I am confused by the number 
of different options to do this.


   command line  config option
--   -
1 i3 --shmlog-size=X shmlog on|off|toggle|
2  i3 -V ?
3  i3 -d all ?
4  ? debuglog on|off|toggle

So my question are:

Which one is the recommended way ?
Does `shmlog on` imply  `debuglog on` ?
Does `-d all` imply `-V` ?
What size do you recommend for the shmlog size ?
May I assume that the config options cannot be used to debug issues 
prior to loading the configuration file (nor issues while loading the 
configuration file) ?
Which of these options provide enough information for a bug report ? Is 
-V enough ?


It seems that shm logging is better in the sense that it does not 
increase a log file size, but not as nice as it locks some memory space.
What is the reason behind shm logging, instead of the usual logging to 
file + logrotate ?


Best regards,
Layus.

--
PS: Some references
http://i3wm.org/docs/debugging.html (--shmlog)
http://i3wm.org/docs/debugging-release-version.html (-V, -d all)
http://i3wm.org/docs/userguide.html#_enabling_debug_logging (debuglog, 
shmlog)