Date: Tue, 27 Jan 2009 16:50:44 +0100
From: Ingo Molnar <mingo@elte.hu>
To: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Tejun Heo <htejun@gmail.com>, Brian Gerst <brgerst@gmail.com>,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2 #tj-percpu] x86: fix build breakage on voyage
Message-ID: <20090127155044.GB28209@elte.hu>
References: <20090126103243.GA31307@elte.hu> <1232977445-11815-1-git-send-email-brgerst@gmail.com> <20090126141832.GA31442@elte.hu> <497E6B34.1020508@kernel.org> <497E8778.9060503@gmail.com> <1233032609.3248.78.camel@localhost.localdomain> <497E9B9D.4010102@gmail.com> <20090127113734.GA28249@elte.hu> <1233070302.3231.34.camel@localhost.localdomain>
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* James Bottomley <James.Bottomley@HansenPartnership.com> wrote:

> On Tue, 2009-01-27 at 12:37 +0100, Ingo Molnar wrote:
> > * Tejun Heo <htejun@gmail.com> wrote:
> > 
> > > From: James Bottomley <James.Bottomley@HansenPartnership.com>
> > > 
> > > Impact: build fix
> > > 
> > > x86_cpu_to_apicid and x86_bios_cpu_apicid aren't defined for voyage. 
> > > Earlier patch forgot to conditionalize early percpu clearing.  Fix it.
> > 
> > > +#ifdef CONFIG_X86_LOCAL_APIC
> > >  	early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
> > >  	early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
> > > +#endif
> > 
> > That patch is not acceptable - it is ugly and it adds another set of
> > #ifdefs to an already complex piece of code.
> > 
> > As i explained it to James in recent threads, the clean and acceptable 
> > solution to this class of problems is to switch Voyager away from that 
> > fragile subarch code to proper generic x86 code. (just like we did it for 
> > other subarchitectures)
> > 
> > There is nothing in Voyager that justifies special treatment in the area 
> > of x86 percpu code.
> > 
> > This is one of the mails that explains the principles:
> > 
> >   http://lkml.indiana.edu/hypermail/linux/kernel/0901.2/00954.html
> > 
> > Or - if there's no time/interest in doing that, we can mark Voyager as 
> > CONFIG_BROKEN.
> 
> Have you quite finished?

What is that supposed to mean?

	Ingo
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