linux-kernel - Re: [PATCH 06/14] [media] cx18: Use current logging styles

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <40a27a5f-f4ec-4304-88a1-a254c7bc6c68@email.android.com>
Date:	Sat, 27 Aug 2011 13:23:14 -0400
From:	Andy Walls <awalls@...metrocast.net>
To:	Joe Perches <joe@...ches.com>
CC:	Mauro Carvalho Chehab <mchehab@...radead.org>,
	ivtv-devel@...vdriver.org, linux-media@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 06/14] [media] cx18: Use current logging styles

Joe Perches <joe@...ches.com> wrote:

>On Sat, 2011-08-27 at 09:28 -0400, Andy Walls wrote:
>> On Wed, 2011-08-24 at 14:42 -0700, Joe Perches wrote:
>> > On Wed, 2011-08-24 at 06:34 -0400, Andy Walls wrote:
>> > > On Sun, 2011-08-21 at 15:56 -0700, Joe Perches wrote:
>> > > > Add pr_fmt.
>> > > > Convert printks to pr_<level>.
>> > > > Convert printks without KERN_<level> to appropriate pr_<level>.
>> > > > Removed embedded prefixes when pr_fmt was added.
>> > > > Use ##__VA_ARGS__ for variadic macros.
>> > > > Coalesce format strings.
>> > > 1. It is important to preserve the per-card prefixes emitted by
>the
>> > > driver: cx18-0, cx18-1, cx18-2, etc.  With a quick skim, I think
>your
>> > > change preserves the format of all output messages (except
>removing
>> > > periods).  Can you confirm this?
>> > Here's the output diff of
>> > strings built-in.o | grep "^<.>" | sort
>> > new and old
>[]
>> Yuck.
>> > > 2. PLease don't add a pr_fmt() #define to exevry file.  Just put
>one
>> > > where all the other CX18_*() macros are defined.  Every file
>picks those
>> > > up.
>> > It's not the first #include of every file.
>> > printk.h has a default #define pr_fmt(fmt) fmt
>> Well then don't use "pr_fmt(fmt)" in cx18, if it overloads a define
>> somewhere else in the kernel and has a dependency on its order
>relative
>> to #include statements.  That sort of thing just ups maintenance
>hours
>> later.  That's not a good trade off for subjectively better log
>> messages.
>> Won't redifining the 'pr_fmt(fmt)' generate preprocessor warnings
>> anyway?
>
>No.
>
>Andy, I fully understand how this stuff works.
>You apparently don't (yet).
>
>Look at include/linux/printk.h
>
>#ifndef pr_fmt
>#define pr_fmt(fmt) fmt
>#endif
>
>A default empty define is used when one
>is not specified before printk.h is
>included.  kernel.h includes printk.h
>
>v4l2_<level> uses the "name" of the video
>device in its output.  That name may not
>be the same name as the module.
>
>--
>To unsubscribe from this list: send the line "unsubscribe linux-media"
>in
>the body of a message to majordomo@...r.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html

Hi Joe,

I don't need to fully understand it.

This is a happy to glad change with no functional nor performance benefit.  It adds unneeded lines of code to the driver and mangles some of the log messages.

I see no benefit from my perspective.

Regards,
Andy
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/