Re: NS83820 2.6.0-test5 driver seems unstable on IA64

From: Andreas Schwab <schwab_at_suse.de>
Date: 2003-09-24 05:16:33
"David S. Miller" <davem@redhat.com> writes:

> On Tue, 23 Sep 2003 21:09:47 +0200
> Andreas Schwab <schwab@suse.de> wrote:
>
>> The compiler is allowed to take advantage that there are no unaligned
>> accesses.  You need to use compiler extensions (like attribute packed) to
>> stop it from doing this.
>
> That's correct, and if the address is misaligned the cpu "traps"
> and the kernel fixes up the load/store access to fix it up.

Or the compiler generates code to take advantage of the fact that the
lower address bits are zero.

> That's what we're talking about here.

Of course, the kernel language is not ISO C, and never will be.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux AG, Deutschherrnstr. 15-19, D-90429 Nürnberg
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Received on Tue Sep 23 15:19:52 2003

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