Date: Mon, 21 Mar 2005 01:45:05 +0100
From: Adrian Bunk <bunk@stusta.de>
To: Dave Jones <davej@redhat.com>, linux-kernel@vger.kernel.org
Subject: Re: [2.6 patch] i386/x86_64 mpparse.c: kill maxcpus
Message-ID: <20050321004505.GB4449@stusta.de>
References: <20050320192549.GP4449@stusta.de> <20050320224233.GB26230@redhat.com> <20050320231232.GY4449@stusta.de> <20050320233203.GC26230@redhat.com> <20050320235946.GA4449@stusta.de> <20050321000149.GD26230@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20050321000149.GD26230@redhat.com>
User-Agent: Mutt/1.5.6+20040907i
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1887
Lines: 56

On Sun, Mar 20, 2005 at 07:01:49PM -0500, Dave Jones wrote:
> On Mon, Mar 21, 2005 at 12:59:46AM +0100, Adrian Bunk wrote:
>  > On Sun, Mar 20, 2005 at 06:32:03PM -0500, Dave Jones wrote:
>  > > On Mon, Mar 21, 2005 at 12:12:32AM +0100, Adrian Bunk wrote:
>  > >  > On Sun, Mar 20, 2005 at 05:42:34PM -0500, Dave Jones wrote:
>  > >  > > On Sun, Mar 20, 2005 at 08:25:49PM +0100, Adrian Bunk wrote:
>  > >  > >  > Do we really need a global variable that does only hold the value of 
>  > >  > >  > NR_CPUS?
>  > >  > > 
>  > >  > > Yes.
>  > >  > >  
>  > >  > > NR_CPUS = compile time
>  > >  > > maxcpus = boot command line at runtime.
>  > >  > 
>  > >  > If this is how is was expected to work - it isn't exactly what is 
>  > >  > currently implemented.
>  > > 
>  > > It's ugly, as its setting the same thing in two different places, but
>  > > I don't see any obvious reason why it won't work.
>  > >...
>  > 
>  > I might be too dumb, but where are the mpparse.c maxcpus variables ever 
>  > set to any value different from NR_CPUS?
> 
> arch/x86_64/kernel/setup.c:parse_cmdline_early()
> 
> 	...
>         else if (!memcmp(from, "maxcpus=", 8)) {
>             extern unsigned int maxcpus;
> 
>             maxcpus = simple_strtoul(from + 8, NULL, 0);
>         }
> 	...

Ah, thanks.

I didn't see this extern declaration.
(and my test compiles were with SMP=n...)

> 		Dave

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

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