From: Petr Mladek <pmladek@suse.com>
To: jim.cromie@gmail.com
Cc: Jason Baron <jbaron@akamai.com>,
LKML <linux-kernel@vger.kernel.org>,
akpm@linuxfoundation.org, Greg KH <gregkh@linuxfoundation.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Jonathan Corbet <corbet@lwn.net>,
Andrew Morton <akpm@linux-foundation.org>,
Will Deacon <will@kernel.org>, Orson Zhai <orson.zhai@unisoc.com>,
Linux Documentation List <linux-doc@vger.kernel.org>
Subject: Re: [PATCH v3 20/21] dyndbg: add user-flag, negating-flags, and filtering on flags
Date: Fri, 19 Jun 2020 09:45:55 +0200 [thread overview]
Message-ID: <20200619074555.GF3617@alley> (raw)
In-Reply-To: <CAJfuBxwLKDSx6RA_ZOk=eEHw0P3FeAcT=PCr-aHjUFKDS2p8cQ@mail.gmail.com>
On Thu 2020-06-18 13:11:05, jim.cromie@gmail.com wrote:
> On Thu, Jun 18, 2020 at 12:17 PM Jason Baron <jbaron@akamai.com> wrote:
> > Yes, I'm wondering as well if people are really going to use the
> > new flags and filter flags - I mentioned that here:
> > https://lkml.org/lkml/2020/6/12/732
>
> yes, I saw, and replied there.
No, the repply only explains how the interface might be used. There is
no prove that people would actually use it.
> but since that was v1, and we're on v3, we should refresh.
>
> the central use-case is above, 1-liner version summarized here:
>
> 1- enable sites as you chase a problem with +up
> 2- examine them with grep =pu
> 3- change the set to suit, either by adding or subtracting callsites.
> 4- continue debugging, and changing callsites to suit
> 5- grep =pu control > ~/debugging-session-task1-callsites
> 6- echo up-p >control # disable for now, leave u-set for later
> 7- do other stuff
> 8 echo uP+p >control # reactivate useful debug-state and resume
In short, this feature allows repeatedly enable/disable some
slowly growing maze of debug messages. Who need this, please? !!!
If I am debugging then I add/remove debug messages. But I never
enable/disable all of them repeatedly.
Also this is far from the original problem. It was about debugging
a single driver (venus, drm). In this case, people need something
easy to use. The following is the easy way:
drm.debug = area_of_interest
venus.debug = level_of_interest
echo module=drm group=area_of_interest +p >control [*]
echo module=venus group=level_of_interes +p >control
Anyway, why filtering and 'u' flag would be necessary to debug these drivers?
Is anyone going to use it?
I would really like to hear the motivation for these features.
Has anyone asked for them?
Or are these just some "interesting" ideas from some brainstorming?
[*] Well, I wonder if the dyndbg interface would even be useful for drm
because it it is actually split into many modules. So it might require
creating/maintaining several filters.
Best Regards,
Petr
PS: This is probably my last mail in this thread. It goes in cycle.
You repeatedly explain how many possibilities the new features
allow. I repeatedly doubt that they are worth it.
I also proposed another solution for the original problem (venus)
but it has never been commented.
I just hope that these features will not get merged without
a clear interest in them.
next prev parent reply other threads:[~2020-06-19 7:46 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-17 16:25 [PATCH v3 00/21] dynamic_debug cleanups, query features, export Jim Cromie
2020-06-17 16:25 ` [PATCH v3 01/21] dyndbg-docs: eschew file /full/path query in docs Jim Cromie
2020-06-17 16:25 ` [PATCH v3 02/21] dyndbg-docs: initialization is done early, not arch Jim Cromie
2020-06-17 16:25 ` [PATCH v3 03/21] dyndbg: drop obsolete comment on ddebug_proc_open Jim Cromie
2020-06-17 16:25 ` [PATCH v3 04/21] dyndbg: refine debug verbosity; 1 is basic, 2 more chatty Jim Cromie
2020-06-17 16:25 ` [PATCH v3 05/21] dyndbg: rename __verbose section to __dyndbg Jim Cromie
2020-06-17 16:25 ` [PATCH v3 06/21] dyndbg: fix overcounting of ram used by dyndbg Jim Cromie
2020-06-17 16:25 ` [PATCH v3 07/21] dyndbg: fix a BUG_ON in ddebug_describe_flags Jim Cromie
2020-06-17 16:25 ` [PATCH v3 08/21] dyndbg: fix pr_err with empty string Jim Cromie
2020-06-17 16:25 ` [PATCH v3 09/21] dyndbg: prefer declarative init in caller, to memset in callee Jim Cromie
2020-06-17 16:25 ` [PATCH v3 10/21] dyndbg: make ddebug_tables list LIFO for add/remove_module Jim Cromie
2020-06-17 16:25 ` [PATCH v3 11/21] dyndbg: use gcc ?: to reduce word count Jim Cromie
2020-06-17 16:25 ` [PATCH v3 12/21] dyndbg: refactor parse_linerange out of ddebug_parse_query Jim Cromie
2020-06-17 16:25 ` [PATCH v3 13/21] dyndbg: accept 'file foo.c:func1' and 'file foo.c:10-100' Jim Cromie
2020-06-17 16:25 ` [PATCH v3 14/21] dyndbg: accept query terms like file=bar and module=foo Jim Cromie
2020-06-18 22:25 ` jim.cromie
2020-06-17 16:25 ` [PATCH v3 14/21] dyndbg: accept query terms like file=bar module=foo Jim Cromie
2020-06-17 16:25 ` [PATCH v3 14/21] dyndbg: accept query terms like module:foo and file=bar Jim Cromie
2020-06-17 16:25 ` [PATCH v3 15/21] dyndbg: export ddebug_exec_queries Jim Cromie
2020-06-17 16:25 ` [PATCH v3 16/21] dyndbg: combine flags & mask into a struct, simplify with it Jim Cromie
2020-06-17 16:25 ` [PATCH v3 17/21] dyndbg: refactor ddebug_read_flags out of ddebug_parse_flags Jim Cromie
2020-06-17 16:25 ` [PATCH v3 18/21] dyndbg: add filter channel to the internals Jim Cromie
2020-06-17 16:25 ` [PATCH v3 19/21] dyndbg: extend ddebug_parse_flags to accept optional leading filter-flags Jim Cromie
2020-06-18 12:44 ` Petr Mladek
2020-06-18 14:54 ` jim.cromie
2020-06-18 16:01 ` Petr Mladek
2020-06-17 16:25 ` [PATCH v3 20/21] dyndbg: add user-flag, negating-flags, and filtering on flags Jim Cromie
2020-06-17 22:13 ` Joe Perches
2020-06-17 22:57 ` jim.cromie
2020-06-18 16:19 ` Petr Mladek
2020-06-18 17:40 ` Petr Mladek
2020-06-18 18:17 ` Jason Baron
2020-06-18 19:11 ` jim.cromie
2020-06-18 19:40 ` Jason Baron
2020-06-18 21:31 ` jim.cromie
2020-06-18 22:34 ` Stanimir Varbanov
2020-06-18 22:48 ` jim.cromie
2020-06-19 16:07 ` Jason Baron
2020-06-19 7:45 ` Petr Mladek [this message]
2020-06-19 8:10 ` Petr Mladek
2020-06-19 8:34 ` Greg KH
2020-06-18 18:15 ` jim.cromie
2020-06-17 16:25 ` [PATCH v3 21/21] dyndbg: allow negating flag-chars in modifier flags Jim Cromie
2020-06-17 20:05 ` [PATCH v3 00/21] dynamic_debug cleanups, query features, export Rasmus Villemoes
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200619074555.GF3617@alley \
--to=pmladek@suse.com \
--cc=akpm@linux-foundation.org \
--cc=akpm@linuxfoundation.org \
--cc=corbet@lwn.net \
--cc=gregkh@linuxfoundation.org \
--cc=jbaron@akamai.com \
--cc=jim.cromie@gmail.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@rasmusvillemoes.dk \
--cc=orson.zhai@unisoc.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).