Re: [PATCH v2] fix sign extension with 1.5TB usb-storage LBD=y

From: Boaz Harrosh
Date: Wed Apr 22 2009 - 07:27:53 EST


On 04/22/2009 02:09 PM, Matthew Wilcox wrote:
> On Wed, Apr 22, 2009 at 10:32:59AM +0300, Boaz Harrosh wrote:
>> These are actually aligned access it might be worth sacrificing a cast
>> to be32/64 for sake of speed.
>
> "for sake of speed"? How often do you think we ask a device how large
> it is?

OK, that was the wrong choice of words, on my part. I meant for sake of
"nobleness". I calculated as a programmer that these are aligned do I make
the extra effort of stating that in code, or I get lazy because it does
not matter?

> How much overhead do you think is incurred by the unaligned code
> if the data happens to be aligned?
>

Well for BE systems we are already order of magnitude faster by just
using the accessors, so I guess we are already well in the "plus" ;)

This is such a small matter, sorry to bother you about it.
Just that it's a programming style I'm constantly debating with myself,
feel free to ignore it.

The patch looks very good to me as it is.

Thanks
Boaz
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