From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.nokia.com ([192.100.122.230] helo=mgw-mx03.nokia.com) by casper.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1LcG9T-00065r-9Y for linux-mtd@lists.infradead.org; Wed, 25 Feb 2009 09:34:05 +0000 Subject: Re: query on UBIFS From: Artem Bityutskiy To: Chakradhar thota In-Reply-To: <8ccea6aa0902240910k6da07085u7e122cb010a99a02@mail.gmail.com> References: <8ccea6aa0902240910k6da07085u7e122cb010a99a02@mail.gmail.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 25 Feb 2009 11:30:28 +0200 Message-Id: <1235554228.25808.24.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: linux-mtd@lists.infradead.org Reply-To: dedekind@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 2009-02-24 at 22:40 +0530, Chakradhar thota wrote: > Hi , > > I am in the process of using UBIfs on my embedded device. > but i came across that JFFS2 cannot be used as swap partition. > what about UBIfs? will UBIfs support swap paritition? > what are the various issues to be taken care if it supports? > thanks in advance. Hi, we never kept this use-case in mind. I do not think it is a brilliant idea to use UBIFS for swap. First of all - why not UBI? It would be smarter to create a simple FTL on top of UBI and put swap there. But you would anyway have to take a look into UBI/mtd and make sure they do not allocate RAM on their paths. Or if they do, they should have some RAM reserve to use if the I/O is swapping. Indeed, if we are swapping because of memory-shortage condition, we should not allocate RAM. Off the top of my head, UBI does allocate RAM when doing I/O. But this can be fixed. To put it simpler, if you want swapping on NAND, you should invest time and make SW engineers look at this. You cannot just take what we have now and start swapping. -- Best regards, Artem Bityutskiy (Битюцкий Артём)