From: Brian Norris <computersforpeace@gmail.com>
To: Joe Perches <joe@perches.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>,
Scott Branden <sbranden@broadcom.com>,
linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org,
Jiandong Zheng <jdzheng@broadcom.com>,
akpm@linux-foundation.org, David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH] mtd/nand: use string library
Date: Fri, 27 Jan 2012 10:52:49 -0800 [thread overview]
Message-ID: <CAN8TOE8Hq8f3ipQFxBAHXK5ArSH6wNc8GA5CbYr_xORBa5gAWw@mail.gmail.com> (raw)
In-Reply-To: <1327684589.12089.22.camel@joe2Laptop>
On Fri, Jan 27, 2012 at 9:16 AM, Joe Perches <joe@perches.com> wrote:
> On Fri, 2012-01-27 at 23:24 +0900, Akinobu Mita wrote:
>> - Use memchr_inv to check if the data contains all 0xFF bytes.
>> It is faster than looping for each byte.
>
> Stupid question:
>
> Are there any mtd devices modified that are slower
> at 64 bit accesses than repeated 8 bit accesses?
I believe this patch deals with kernel buffers, not any kind of direct
access to the MTD, so the question (which is not stupid IMO) should be
regarding CPU architectures. And my educated guess is that 64-bit
access should not be any slower. I do know that 8-bit access *is*
slower for some relevant architectures.
Brian
next prev parent reply other threads:[~2012-01-27 18:52 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-27 14:24 [PATCH] powerpc: use string library Akinobu Mita
2012-01-27 14:24 ` [PATCH] mtd/nand: " Akinobu Mita
2012-01-27 17:16 ` Joe Perches
2012-01-27 18:52 ` Brian Norris [this message]
2012-01-27 23:52 ` Akinobu Mita
2012-01-31 17:57 ` Brian Norris
2012-02-01 13:11 ` Akinobu Mita
2012-01-27 14:24 ` [PATCH] mtd/onenand: " Akinobu Mita
2012-01-27 14:24 ` [PATCH] mtd/ubi: use memchr_inv Akinobu Mita
2012-01-27 14:24 ` [PATCH] mtd/inftlmount: " Akinobu Mita
2012-01-27 14:24 ` [PATCH] mtd/nftlmount: " Akinobu Mita
2012-01-27 14:24 ` [PATCH] mtd/tests: " Akinobu Mita
2012-01-27 14:24 ` [PATCH] mISDN: " Akinobu Mita
2012-02-01 19:15 ` David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAN8TOE8Hq8f3ipQFxBAHXK5ArSH6wNc8GA5CbYr_xORBa5gAWw@mail.gmail.com \
--to=computersforpeace@gmail.com \
--cc=akinobu.mita@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=dwmw2@infradead.org \
--cc=jdzheng@broadcom.com \
--cc=joe@perches.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=sbranden@broadcom.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).