From: Jason Baron <jbaron@redhat.com>
To: Jonathan Corbet <corbet@lwn.net>
Cc: jim.cromie@gmail.com, joe@perches.com, bart.vanassche@gmail.com,
greg@kroah.com, linux-kernel@vger.kernel.org, trenn@suse.de
Subject: Re: [PATCH 23/26] dynamic_debug: document pending queries, flags-filter, multiple queries
Date: Mon, 10 Oct 2011 15:27:32 -0400 [thread overview]
Message-ID: <20111010192732.GB2413@redhat.com> (raw)
In-Reply-To: <20111010125445.3a1248e4@bike.lwn.net>
On Mon, Oct 10, 2011 at 12:54:45PM -0600, Jonathan Corbet wrote:
> > +
> > +Queries submitted with 'a' are applied to current callsites as above,
> > +but are also added to a pending list. When a module is loaded later,
> > +pending queries are applied to the module in the order given.
> > +
> > +This is done before the module_init() routine is run, so pr_debug()s
> > +can be active during initialization. To better support module
> > +debugging, pending queries remain on the list through modprobe-rmmod
> > +cycles.
>
> So this functionality seems to be the whole point of much of this patch
> set. That's a lot of stuff to turn on printks during module_init(). I
> can't help but wonder: wouldn't it be easier and better to just recognize
> the ddebug_query= parameter at module load time? Then you could drop this
> whole pending queries mechanism, the expanded syntax, new control file, and
> so on...? What am I missing?
>
Hi,
Thanks for providing feedback on these patches. There was indeed an
earlier approach to do this as a module parameter:
https://lkml.org/lkml/2010/9/15/397
This never quite got merged b/c I believe there were some build issues,
that never got completely resolved. I've added Thomas Renninger, the
author of that earlier appraoch to the 'cc list here.
One concern with the module parameter approach was that it reserves a
module parameter name for all modules, but perhaps if its
'ddebug_query=' that is ok. Also, I think the implmentation was
basically pass 'ddebug' as module param and it becomes:
'ddebug_query=module foo +p'. So perhaps, we could have it pass on a
full query string.
But yes, I agree the module param approach may be simpler...
Thanks,
-Jason
next prev parent reply other threads:[~2011-10-10 19:27 UTC|newest]
Thread overview: 82+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-21 21:54 jim.cromie
2011-09-21 21:54 ` [PATCH 01/26] dynamic_debug: drop enabled field from struct _ddebug, use flags & _DPRINTK_FLAGS_PRINT jim.cromie
2011-09-21 21:54 ` [PATCH 02/26] dynamic_debug: make dynamic-debug supersede DEBUG ccflag jim.cromie
2011-09-21 21:54 ` [PATCH 03/26] dynamic_debug: replace strcpy with strlcpy, in ddebug_setup_query() jim.cromie
2011-09-21 21:54 ` [PATCH 04/26] dynamic_debug: warn when >1 of each type of match-spec is given jim.cromie
2011-09-21 21:54 ` [PATCH 05/26] dynamic_debug: pr_err() call should not depend upon verbosity jim.cromie
2011-09-21 21:54 ` [PATCH 06/26] dynamic_debug: add trim_prefix() to provide source-root relative paths jim.cromie
2011-09-21 21:54 ` [PATCH 07/26] dynamic_debug: change verbosity at runtime jim.cromie
2011-09-21 21:54 ` [PATCH 08/26] dynamic_debug: define several levels of verbosity jim.cromie
2011-09-21 21:54 ` [PATCH 09/26] dynamic_debug: process multiple commands on a line jim.cromie
2011-09-21 21:54 ` [PATCH 10/26] dynamic_debug: enlarge command/query write buffer jim.cromie
2011-09-21 22:29 ` Joe Perches
2011-09-21 21:55 ` [PATCH 11/26] dynamic_debug: hoist locking in ddebug_change to callers jim.cromie
2011-09-21 21:55 ` [PATCH 12/26] dynamic_debug: dont kill entire facility on error parsing ddebug_query jim.cromie
2011-09-21 21:55 ` [PATCH 13/26] dynamic_debug: factor vpr_info_dq out of ddebug_parse_query jim.cromie
2011-09-21 21:55 ` [PATCH 14/26] dynamic_debug: refactor query_matches_callsite out of ddebug_change jim.cromie
2011-09-21 21:55 ` [PATCH 15/26] dynamic_debug: drop explicit foo != NULL checks jim.cromie
2011-09-21 21:55 ` [PATCH 16/26] dynamic_debug: save 'a' queries to pending-list for later (re)application jim.cromie
2011-09-21 21:55 ` [PATCH 17/26] dynamic_debug: remove pending query when flags zeroed jim.cromie
2011-09-21 21:55 ` [PATCH 18/26] dynamic_debug: describe_flags with '=[pmflta_]*' jim.cromie
2011-09-21 21:55 ` [PATCH 19/26] dynamic_debug: add flags filtering to flags spec jim.cromie
2011-09-21 21:55 ` [PATCH 20/26] dynamic_debug: make ddebug_describe_flags more generic jim.cromie
2011-09-21 21:55 ` [PATCH 21/26] dynamic_debug: add $DBGFS/dynamic_debug/pending file jim.cromie
2011-09-21 21:55 ` [PATCH 22/26] dynamic_debug: early return if _ddebug table is empty jim.cromie
2011-09-21 21:55 ` [PATCH 23/26] dynamic_debug: document pending queries, flags-filter, multiple queries jim.cromie
2011-09-21 22:35 ` Randy Dunlap
2011-09-27 16:33 ` [patch 23/26 revised] jim.cromie
2011-09-27 16:33 ` [PATCH 23/26] dynamic_debug: document pending queries, flags-filter, multiple queries jim.cromie
2011-10-10 18:54 ` Jonathan Corbet
2011-10-10 19:27 ` Jason Baron [this message]
2011-10-18 20:41 ` Jim Cromie
2011-10-19 20:52 ` Jason Baron
2011-09-21 21:55 ` [PATCH 24/26] dynamic_debug: reduce lineno field to a saner 18 bits jim.cromie
2011-09-21 21:55 ` [PATCH 25/26] dynamic_debug: add pr_fmt_dbg() for dynamic_pr_debug jim.cromie
2011-09-22 20:57 ` Joe Perches
2011-09-23 10:31 ` Bart Van Assche
2011-09-23 17:42 ` Joe Perches
2011-09-27 20:37 ` Jim Cromie
2011-09-27 23:36 ` Joe Perches
2011-09-28 2:54 ` Jim Cromie
2011-09-28 4:51 ` Joe Perches
2011-09-28 17:27 ` Jim Cromie
2011-09-29 15:24 ` Joe Perches
2011-10-08 19:07 ` Bart Van Assche
2011-10-08 20:53 ` Joe Perches
2011-09-27 21:40 ` [revised patches 25,26/26] dynamic_debug: add pr_fmt_*() jim.cromie
2011-09-27 21:40 ` [PATCH 25/26] dynamic_debug: add pr_fmt_debug() for dynamic_pr_debug jim.cromie
2011-09-27 21:41 ` [PATCH 26/26] scx200_acb: use pr_(info|warn|err|debug) and dynamic-debug facilities jim.cromie
2011-09-21 21:55 ` jim.cromie
2011-09-26 23:23 ` your mail Greg KH
2011-10-07 20:33 ` [PATCH 00/26] dynamic_debug: add pending queries, etc (~resend) jim.cromie
2011-10-07 20:33 ` [PATCH 01/26] dynamic_debug: drop enabled field from struct _ddebug, use flags & _DPRINTK_FLAGS_PRINT jim.cromie
2011-10-07 20:33 ` [PATCH 02/26] dynamic_debug: make dynamic-debug supersede DEBUG ccflag jim.cromie
2011-10-07 20:33 ` [PATCH 03/26] dynamic_debug: replace strcpy with strlcpy, in ddebug_setup_query() jim.cromie
2011-10-07 20:33 ` [PATCH 04/26] dynamic_debug: warn when >1 of each type of match-spec is given jim.cromie
2011-10-07 20:33 ` [PATCH 05/26] dynamic_debug: pr_err() call should not depend upon verbosity jim.cromie
2011-10-07 21:21 ` Joe Perches
2011-10-07 20:33 ` [PATCH 06/26] dynamic_debug: add trim_prefix() to provide source-root relative paths jim.cromie
2011-10-07 20:33 ` [PATCH 07/26] dynamic_debug: change verbosity at runtime jim.cromie
2011-10-07 20:33 ` [PATCH 08/26] dynamic_debug: define several levels of verbosity jim.cromie
2011-10-07 20:33 ` [PATCH 09/26] dynamic_debug: process multiple commands on a line jim.cromie
2011-10-07 20:33 ` [PATCH 10/26] dynamic_debug: enlarge command/query write buffer jim.cromie
2011-10-07 20:33 ` [PATCH 11/26] dynamic_debug: hoist locking in ddebug_change to callers jim.cromie
2011-10-07 20:33 ` [PATCH 12/26] dynamic_debug: dont kill entire facility on error parsing ddebug_query jim.cromie
2011-10-07 20:33 ` [PATCH 13/26] dynamic_debug: factor vpr_info_dq out of ddebug_parse_query jim.cromie
2011-10-07 20:33 ` [PATCH 14/26] dynamic_debug: refactor query_matches_callsite out of ddebug_change jim.cromie
2011-10-07 20:33 ` [PATCH 15/26] dynamic_debug: drop explicit foo != NULL checks jim.cromie
2011-10-07 20:33 ` [PATCH 16/26] dynamic_debug: save 'a' queries to pending-list for later (re)application jim.cromie
2011-10-07 20:33 ` [PATCH 17/26] dynamic_debug: remove pending query when flags zeroed jim.cromie
2011-10-07 20:33 ` [PATCH 18/26] dynamic_debug: describe_flags with '=[pmflta_]*' jim.cromie
2011-10-07 20:33 ` [PATCH 19/26] dynamic_debug: add flags filtering to flags spec jim.cromie
2011-10-07 20:33 ` [PATCH 20/26] dynamic_debug: make ddebug_describe_flags more generic jim.cromie
2011-10-07 20:33 ` [PATCH 21/26] dynamic_debug: add $DBGFS/dynamic_debug/pending file jim.cromie
2011-10-07 20:33 ` [PATCH 22/26] dynamic_debug: early return if _ddebug table is empty jim.cromie
2011-10-07 20:33 ` [PATCH 23/26] dynamic_debug: document pending queries, flags-filter, multiple queries jim.cromie
2011-10-07 20:33 ` [PATCH 24/26] dynamic_debug: reduce lineno field to a saner 18 bits jim.cromie
2011-10-07 20:33 ` [PATCH 25/26] dynamic_debug: add pr_fmt_*() for each severity jim.cromie
2011-10-07 20:33 ` [PATCH 26/26] printk.h: fix pr_cont_once() to not use pr_fmt() jim.cromie
2011-10-07 20:45 ` Joe Perches
2011-10-18 18:52 ` [PATCH 00/26] dynamic_debug: add pending queries, etc (~resend) Greg KH
2011-10-19 20:57 ` Jason Baron
2011-10-19 22:29 ` Greg KH
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=20111010192732.GB2413@redhat.com \
--to=jbaron@redhat.com \
--cc=bart.vanassche@gmail.com \
--cc=corbet@lwn.net \
--cc=greg@kroah.com \
--cc=jim.cromie@gmail.com \
--cc=joe@perches.com \
--cc=linux-kernel@vger.kernel.org \
--cc=trenn@suse.de \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.