Subject: Re: 2.6 must-fix list, v2
From: Steven Cole <elenstev@mesatop.com>
To: "Shaheed R. Haque" <srhaque@iee.org>
Cc: Andrew Morton <akpm@digeo.com>, linux-kernel@vger.kernel.org
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On Tue, 2003-05-13 at 16:46, Shaheed R. Haque wrote:
> Quoting Andrew Morton <akpm@digeo.com>:
> 
> > "Shaheed R. Haque" <srhaque@iee.org> wrote:
> > >
> > > - Add ability to restrict the the default CPU affinity mask so that 
> > >  sys_setaffinity() can be used to implement exclusive access to a CPU.
> > 
> > Why is this useful?
> 
> Because it allows one to dedicate a CPU to a process. For example, lets say you
> have a quad processor,and want to run joe-random stuff on CPU 0, but a
> specialised program on CPUs 1, 2, 3 that does not want to compete with
> joe-random stuff.
> 
> With sys_setaffinity(), one can set the affinity of the special program to
> 0xe...but the default affinity for all the joe-random stuff is still 0xf (from
> cpu_online_map)! Since its impractical to to modify every single joe-random
> executable to set its affinity to 0x1, a way is needed to set the default. The
> logical place is in init(), a.k.a. kernel/fork.c.
> 
> I hope that make sense.
> 
> Thanks, Shaheed
> 

Is this related or not to processor shielding used by RedHawk Linux?
Here is a link to their page:

http://www.ccur.com/realtime/sys_rdhwklnx.html

I saw a presentation by these guys over a year ago.  I'm not sure what
they're up to now.

Steven

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