OneNAND: read-while-load

[Kyungmin Park <kyungmin.park@samsung.com>]

Yes, We already knew read-while-loading has better performance than normal read.
Internally we called it 'MRead' (refer another OneNAND open source in samsung web site)

Currently it is best one if the JFFS2 requests read 4KB or more.
and if you are using the mtdblock. it also has benefits

Thank you,
Kyungmin Park

------- Original Message -------
Sender : Artem Bityutskiy<dedekind@infradead.org> 
Date   : Jan 05, 2007 18:01
Title  : Re: OneNAND: read-while-load

Kyungmin, Adrian,

On Fri, 2007-01-05 at 07:15 +0000, Kyungmin Park wrote:
> I will run regression test with this one during this weekend.
> 
> And which program (JFFS2 or UBI) do you use.
> 
> I can't find any performance increase in JFFS2

It depends how you tested it. Surely you notice some performance gain
only if JFFS2 reads more then 2K bytes of data. And this only happens
when you read files's contents, especially if this file's pages were not
compressed to less then 2K.

So a test like:

dd if=/dev/udandom of=/mnt/jffs2/file bs=4K
time dd if=/mnt/jffs2/file of=/dev/null

would be roughly OK.

-- 
Best regards,
Artem Bityutskiy (Битюцкий Артём)