From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Chubb Date: Tue, 23 Sep 2003 10:40:05 +0000 Subject: Re: NS83820 2.6.0-test5 driver seems unstable on IA64 Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org >>>>> "David" = David S Miller writes: David> On Mon, 22 Sep 2003 20:36:29 -0400 Benjamin LaHaise David> wrote: >> Denied. Dave, please explain. David> Why should I have anything to explain? :-) David> The fact that ia64 is doing a printk for an unaligned kernel David> load or store is what you should be asking questions about :) How expensive is it to take the trap and do a fix up, compared to making an aligned copy? As it involves raising and handling a fault disassembling the instruction that caused the fault, etc., I'd be surprised if it's much less than 1000 cycles, even without the printk, although I haven't measured it yet, and can't find enough info in the architecture manuals to know what it is. Even if it's only 500 cycles, you can copy and realign a large packet in that time. -- Dr Peter Chubb http://www.gelato.unsw.edu.au peterc AT gelato.unsw.edu.au You are lost in a maze of BitKeeper repositories, all slightly different.