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From: Boaz Harrosh <bharrosh@panasas.com>
To: Matthew Wilcox <matthew@wil.cx>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	mdharm-usb@one-eyed-alien.net,
	linux-usb <linux-usb@vger.kernel.org>,
	usb-storage@lists.one-eyed-alien.net,
	James Bottomley <James.Bottomley@HansenPartnership.com>,
	linux-scsi <linux-scsi@vger.kernel.org>,
	viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH v2] fix sign extension with 1.5TB usb-storage LBD=y
Date: Wed, 22 Apr 2009 14:27:12 +0300	[thread overview]
Message-ID: <49EEFF10.3050306@panasas.com> (raw)
In-Reply-To: <20090422110921.GE1926@parisc-linux.org>

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

  reply	other threads:[~2009-04-22 11:27 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-21 20:52 [RFC][PATCH] fix sign extension with 1.5TB usb-storage LBD=y Dave Hansen
2009-04-21 21:01 ` Al Viro
2009-04-21 21:18 ` Matthew Wilcox
2009-04-21 22:00   ` [PATCH v2] " Dave Hansen
2009-04-21 23:03     ` Matthew Wilcox
2009-04-21 23:43       ` Dave Hansen
2009-04-22  7:32     ` Boaz Harrosh
     [not found]       ` <49EEC82B.5040603-C4P08NqkoRlBDgjK7y7TUQ@public.gmane.org>
2009-04-22 11:09         ` Matthew Wilcox
2009-04-22 11:27           ` Boaz Harrosh [this message]
     [not found]   ` <20090421211858.GA1926-6jwH94ZQLHl74goWV3ctuw@public.gmane.org>
2009-04-21 21:29     ` [RFC][PATCH] " Randy Dunlap
2009-04-21 21:31       ` Matthew Wilcox
2009-04-21 22:49     ` Dave Hansen

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