Date: Wed, 2 May 2007 00:07:45 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Bill Irwin <bill.irwin@oracle.com>
Cc: Matt Mackall <mpm@selenic.com>, Christoph Hellwig <hch@infradead.org>,
       Andi Kleen <andi@firstfloor.org>, David Chinner <dgc@sgi.com>,
       Zan Lynx <zlynx@acm.org>, Adrian Bunk <bunk@stusta.de>,
       Linux Kernel <linux-kernel@vger.kernel.org>, wli@holomorphy.com
Subject: Re: [2/6] add config option to vmalloc stacks (was: Re: [-mm patch]
 i386: enable 4k stacks by default)
Message-ID: <20070502000745.3a819160@the-village.bc.nu>
In-Reply-To: <20070501225125.GU26598@holomorphy.com>
References: <20070430091754.24df88df@the-village.bc.nu>
	<p73wszuyx7h.fsf@bingen.suse.de>
	<20070430104806.GA14944@infradead.org>
	<p73slaiys9v.fsf@bingen.suse.de>
	<20070430173819.GC19966@holomorphy.com>
	<20070430174310.GE19966@holomorphy.com>
	<20070430181104.GB14739@infradead.org>
	<20070430190952.GP31925@holomorphy.com>
	<20070430191511.GA25318@infradead.org>
	<20070501223606.GQ11166@waste.org>
	<20070501225125.GU26598@holomorphy.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 584
Lines: 14

> These IRQ stacks are per-cpu, not per-IRQ. It may make sense to
> implement per-IRQ stacks, in which case dynamic allocation at the time
> of request_irq() will make sense.

This depends if active IRQ count exceeds active CPU count worst cases.
For the big boxes it might well do but for small ones we seem to be best
with per CPU.

Alan
-
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/