Date: Fri, 16 Feb 2007 13:41:17 +0100
From: Ingo Molnar <mingo@elte.hu>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
       Linus Torvalds <torvalds@linux-foundation.org>,
       Andrew Morton <akpm@linux-foundation.org>, Andi Kleen <ak@suse.de>,
       Benjamin Herrenschmidt <benh@kernel.crashing.org>,
       Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: [RFC] killing the NR_IRQS arrays.
Message-ID: <20070216124117.GB4218@elte.hu>
References: <m1ire2e20p.fsf@ebiederm.dsl.xmission.com>
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* Eric W. Biederman <ebiederm@xmission.com> wrote:

> So I propose we remove all assumptions from the code that we actually 
> have an array of irqs.  That will allow for irq_desc to be dynamically 
> allocated instead of statically allocated saving memory and reducing 
> kernel complexity.

hm. I'd suggest to do this without changing request_irq() - and then we 
could avoid the 'massive, every driver affected' change, right?

i.e. because we'll (have to) have an nr_to_desc() and desc_to_nr() 
mapping facility anyway, lets just not change the driver APIs massively. 
There dont seem to be that many drivers that assume that irq_desc[] is 
an array - are there?

otherwise, in terms of the irqchips infrastructure and the API between 
genirq and the irqchip arch-level drivers, this change makes quite a bit 
of sense i think.

or am i missing something fundamental?

	Ingo
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