From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from e2.ny.us.ibm.com ([32.97.182.142]) by bombadil.infradead.org with esmtps (Exim 4.68 #1 (Red Hat Linux)) id 1J2Shc-0007qj-Aq for linux-mtd@lists.infradead.org; Wed, 12 Dec 2007 14:36:55 +0000 Received: from d01relay07.pok.ibm.com (d01relay07.pok.ibm.com [9.56.227.147]) by e2.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id lBCEakeY005668 for ; Wed, 12 Dec 2007 09:36:46 -0500 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d01relay07.pok.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id lBCEahJU1138928 for ; Wed, 12 Dec 2007 09:36:43 -0500 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id lBCEagD4011265 for ; Wed, 12 Dec 2007 07:36:42 -0700 Date: Wed, 12 Dec 2007 08:36:39 -0600 From: Josh Boyer To: Alexey Korolev Subject: Re: Limited support of NAND features in MTD. Message-ID: <20071212083639.337f3049@weaponx> In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: dwmw2@infradead.org, joern@logfs.org, linux-mtd@lists.infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 12 Dec 2007 11:51:40 +0000 (GMT) Alexey Korolev wrote: > Hi, > > It is not a secret that current MTD supports very limited set of NAND > features. Some of missed features like partial page read or cached read > are able to improve file system performance and its implementation do > not require s/w redesign. > > I have a question is there any limitations/restrictions to support extended features? > Does it make sense to implement these features and manage them > through nand_chip->options flag, letting people to choose whether to use > features or not? If it is not a good idea what is the best way to manage > it? > > Currently my clooeague and I did prototypes of partial page read and cached read > functionalities showing performance increase. For example partial page read showed about 20% > of file open/stat time performance increase in JFFS2 on LP NAND. Cached > read increases overall read performance but value strongly depends on > platform IO latencies. Now we are thinking to create and sent patches. > > So your suggestions/recomendations are welcome! Here is my suggestion. Create the patches and send them :). More seriously, it is often better to send out patches to show more concretely what you'd like to accomplish. Then people can review them and make suggestions for improvements or changes. I personally find it rewarding to do so even if my patches aren't excepted in the end. I always learn something, and the code is archived for those that want to play with it. josh