From: Bill Davidsen <davidsen@tmr.com>
To: Jaswinder Singh <jaswinderrajput@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: PREEMPT is messing with everyone
Date: Tue, 05 Dec 2006 14:55:24 -0500 [thread overview]
Message-ID: <4575CEAC.2010503@tmr.com> (raw)
In-Reply-To: <aa5953d60612050850v240b382fm172702b1d28934a1@mail.gmail.com>
Jaswinder Singh wrote:
> On 12/5/06, Michal Schmidt <xschmi00@stud.feec.vutbr.cz> wrote:
>> Jaswinder Singh wrote:
>> > Hi,
>> >
>> > preempt stuff SHOULD only stay in #ifdef CONFIG_PREEMP_* , but it is
>> > messing with everyone even though not defined.
>> >
>> > e.g.
>> >
>> > 1. linux-2.6.19/kernel/spinlock.c
>> >
>> > Line 18: #include <linux/preempt.h>
>> >
>> > Line 26: preempt_disable();
>> >
>> > Line 32: preempt_disable();
>> >
>> > and so on .
>>
>> Don't worry. These compile into "do { } while (0)" (i.e. nothing) when
>> CONFIG_PREEMPT is not set.
>>
>
> Yes, Compiler will remove it but this looks ugly and confusing.
>
> Why dont we use like this :-
Because it's ugly and confusing.
>
> #ifdef CONFIG_PREEMPT
> #include <linux/preempt.h>
> #endif
>
> #ifdef CONFIG_PREEMPT
> preempt_disable();
> #endif
>
> #ifdef CONFIG_PREEMPT
> preempt_enable();
> #endif
--
bill davidsen <davidsen@tmr.com>
CTO TMR Associates, Inc
Doing interesting things with small computers since 1979
next prev parent reply other threads:[~2006-12-05 19:51 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-05 14:10 PREEMPT is messing with everyone Jaswinder Singh
2006-12-05 15:08 ` Michal Schmidt
2006-12-05 16:50 ` Jaswinder Singh
2006-12-05 16:58 ` Michal Schmidt
2006-12-05 19:55 ` Bill Davidsen [this message]
2006-12-05 20:30 ` Jan Engelhardt
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=4575CEAC.2010503@tmr.com \
--to=davidsen@tmr.com \
--cc=jaswinderrajput@gmail.com \
--cc=linux-kernel@vger.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