Message-ID: <49EEFF10.3050306@panasas.com>
Date: Wed, 22 Apr 2009 14:27:12 +0300
From: Boaz Harrosh <bharrosh@panasas.com>
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To: Matthew Wilcox <matthew@wil.cx>
CC: Dave Hansen <dave@linux.vnet.ibm.com>,
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       James Bottomley <James.Bottomley@HansenPartnership.com>,
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Subject: Re: [PATCH v2] fix sign extension with 1.5TB usb-storage LBD=y
References: <1240347174.10627.20.camel@nimitz> <20090421211858.GA1926@parisc-linux.org> <1240351210.10627.30.camel@nimitz> <49EEC82B.5040603@panasas.com> <20090422110921.GE1926@parisc-linux.org>
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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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