From: Michal Marek <mmarek@suse•cz>
To: Valdis.Kletnieks@vt•edu
Cc: Armin Schindler <armin@melware•de>,
linux-kbuild@vger•kernel.org, linux-kernel@vger•kernel.org,
netdev@vger•kernel.org
Subject: Re: [PATCH 12/34] isdn/diva: Drop __TIME__ usage
Date: Wed, 06 Apr 2011 10:06:52 +0200 [thread overview]
Message-ID: <4D9C1F1C.50802@suse.cz> (raw)
In-Reply-To: <20627.1302031056@localhost>
On 5.4.2011 21:17, Valdis.Kletnieks@vt•edu wrote:
> On Tue, 05 Apr 2011 17:10:34 +0200, Armin Schindler said:
>> On Tue, 5 Apr 2011, Michal Marek wrote:
>>> The kernel already prints its build timestamp during boot, no need to
>>> repeat it in random drivers and produce different object files each
>>> time.
>>
>> The module can be build separately from the kernel, therefore it can have
>> an own build timestamp.
>
> If the same code is being built as an out-of-tree module, that's a possibly
> good reason for a code version variable, but what does the build timestamp
> actually tell you? If you already know foo_driver.c version 0.814 was buiilt
> against 2.6.41-rc2, in what cases does it matter if the compile was on Tuesday
> or Thursday - especially since an 'ls -l foo_driver.ko' will tell you? If it's
> a matter of "the target .config changed on Wednesday", a build timestamp still
> doesn't help over 'ls -l'.
Exactly. Build timestamps are only a poor substitute for proper version
tracking. If you want to be able to reproduce the build of a binary, you
want it to embed some source revision, not the date when you built it.
For the kernel, you can use KBUILD_BUILD_TIMESTAMP=<source timestamp>,
for out-of-tree modules, you need to come up with something own.
Michal
next prev parent reply other threads:[~2011-04-06 8:06 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-05 14:58 [PATCH 00/34] Make kernel build deterministic Michal Marek
2011-04-05 14:58 ` [PATCH 12/34] isdn/diva: Drop __TIME__ usage Michal Marek
2011-04-05 15:10 ` Armin Schindler
2011-04-05 15:37 ` Ben Hutchings
2011-04-05 16:07 ` Armin Schindler
2011-04-05 20:01 ` Sam Ravnborg
2011-04-05 19:17 ` Valdis.Kletnieks
2011-04-06 8:06 ` Michal Marek [this message]
2011-05-25 20:38 ` Michal Marek
2011-05-26 8:15 ` Armin Schindler
2011-05-26 8:29 ` Michal Marek
2011-04-05 14:59 ` [PATCH 15/34] baycom: " Michal Marek
[not found] ` <1302015780.4124.53.camel@xbox360.hq.axsem.com>
2011-05-25 15:23 ` Michal Marek
2011-04-05 14:59 ` [PATCH 17/34] hdlcdrv: " Michal Marek
2011-04-19 10:17 ` walter harms
2011-04-19 10:56 ` Michal Marek
[not found] ` <1302015790.4124.54.camel@xbox360.hq.axsem.com>
2011-05-25 15:24 ` Michal Marek
2011-04-05 14:59 ` [PATCH 18/34] wan/pc300: " Michal Marek
2011-05-25 20:43 ` Michal Marek
2011-05-25 20:44 ` David Miller
2011-04-05 14:59 ` [PATCH 19/34] rt2x00: " Michal Marek
2011-04-05 15:28 ` Gertjan van Wingerde
2011-04-05 18:37 ` Ivo Van Doorn
2011-04-05 14:59 ` [PATCH 28/34] atm: " Michal Marek
2011-05-25 20:49 ` Michal Marek
2011-05-25 21:39 ` David Miller
2011-04-05 14:59 ` [PATCH 29/34] tipc: " Michal Marek
2011-04-05 22:25 ` Paul Gortmaker
2011-04-05 15:49 ` [PATCH 00/34] Make kernel build deterministic Greg KH
2011-04-05 18:16 ` James Bottomley
2011-04-05 18:29 ` Mauro Carvalho Chehab
2011-04-05 18:44 ` Greg KH
2011-04-05 19:24 ` Artem Bityutskiy
2011-04-06 8:57 ` Ingo Molnar
2011-04-06 9:07 ` Michal Marek
2011-04-06 9:25 ` Artem Bityutskiy
2011-04-06 9:23 ` Michal Marek
2011-04-06 9:01 ` Ingo Molnar
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=4D9C1F1C.50802@suse.cz \
--to=mmarek@suse$(echo .)cz \
--cc=Valdis.Kletnieks@vt$(echo .)edu \
--cc=armin@melware$(echo .)de \
--cc=linux-kbuild@vger$(echo .)kernel.org \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=netdev@vger$(echo .)kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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