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Date: Mon, 21 Apr 2008 19:03:31 -0700 (PDT)
Message-Id: <20080421.190331.58435430.davem@davemloft.net>
To: jeff@garzik.org
Cc: linux-kernel@vger.kernel.org, jens.axboe@oracle.com,
       tsbogend@alpha.franken.de, akpm@linux-foundation.org
Subject: Re: cdrom: use kmalloced buffers instead of buffers on stack
From: David Miller <davem@davemloft.net>
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From: Jeff Garzik <jeff@garzik.org>
Date: Mon, 21 Apr 2008 22:01:26 -0400

> Eh... AFAICS this is only really useful in two of the cases converted.
> 
> For all the other cases (<= 32 bytes), it is _far_ less complex, far 
> less code to simply communicate the additional alignment requirements to 
> the compiler.
> 
> What about __attribute__ __aligned__?  Was that tried?

On some platforms the stack is virtually mapped instead of
from kmalloc or get_free_pages memory.

DMA on stack buffers is really not feasible.