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From: Robert Love <rml@tech9.net>
To: Chuck Ebbert <76306.1226@compuserve.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] New cpu macro and i386 cleanup
Date: 05 Apr 2003 13:56:06 -0500	[thread overview]
Message-ID: <1049568966.753.142.camel@localhost> (raw)
In-Reply-To: <200304050525_MC3-1-331B-F7E3@compuserve.com>

On Sat, 2003-04-05 at 05:24, Chuck Ebbert wrote:

> I was wondering whether the code I converted was running with preempt
> disabled or not but didn't check.  (The very thought of preempt on
> SMP scares me anyway, so I avoid it.)

On a glance, it looked like at least some of them were.

> smp_processor_id() is not preempt-safe either, since the id could
> change before you even get a chance to use the value.  How many
> thousands of lines of code remain that were written assuming things
> would not change underneath them in kernel mode?

Code that needs the processor number to remain fixed now uses get_cpu()
and put_cpu() which disable preemption.

> > Maybe put a comment above it like:
> 
> 
> How about one for the whole kernel?
> 
>         /**********
>          * WARNING: Use preempt at your own risk.
>          **********/

No :)

	Robert Love


  reply	other threads:[~2003-04-05 18:44 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-04-05 10:24 [PATCH] New cpu macro and i386 cleanup Chuck Ebbert
2003-04-05 18:56 ` Robert Love [this message]
  -- strict thread matches above, loose matches on Subject: below --
2003-04-05 22:17 Chuck Ebbert
2003-04-05  0:29 Chuck Ebbert
2003-04-05  1:05 ` Robert Love

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