Date: Wed, 27 Feb 2008 16:02:10 +0100
From: Ingo Molnar <mingo@elte.hu>
To: Nick Piggin <npiggin@suse.de>
Cc: Andi Kleen <ak@suse.de>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       linux-arch@vger.kernel.org
Subject: Re: [rfc][patch] x86-64 new smp_call_function design
Message-ID: <20080227150210.GA21610@elte.hu>
References: <20080227124217.GA1340@wotan.suse.de> <20080227132713.GA13681@elte.hu> <20080227135041.GC1340@wotan.suse.de>
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* Nick Piggin <npiggin@suse.de> wrote:

> > the two structures are quite similar in size and role - why not have 
> > a type field and handle them largely together? I think we should try 
> > to preserve a single queue and a single vector - that would remove a 
> > number of ugly special-cases from the patch.
> 
> A single queue will kill one of the big fundamental scalability 
> improvements of the call_single. That's the problem.

hm, indeed. Then how about the other way around: couldnt the normal 
all-cpus SMP function call be implemented transparently via using 
smp_call_single() calls? The vector duplication is really ugly and feels 
wrong.

	Ingo
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