From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ptb-relay02.plus.net ([212.159.14.213]) by canuck.infradead.org with esmtps (Exim 4.42 #1 (Red Hat Linux)) id 1CfK6G-0005oG-Fn for linux-mtd@lists.infradead.org; Fri, 17 Dec 2004 10:33:04 -0500 From: "Gareth Bult (Encryptec)" To: Josh Boyer In-Reply-To: <1103288058.3018.4.camel@weaponx.rchland.ibm.com> References: <1103152743.15913.33.camel@squizzey.bult.co.uk> <41C0D3AC.3050801@us.ibm.com> <1103158974.15929.37.camel@squizzey.bult.co.uk> <1103201631.25765.7.camel@weaponx.rchland.ibm.com> <1103232128.15927.70.camel@squizzey.bult.co.uk> <41C1FDFF.3020308@us.ibm.com> <1103233669.15929.81.camel@squizzey.bult.co.uk> <1103288058.3018.4.camel@weaponx.rchland.ibm.com> Content-Type: text/plain Date: Fri, 17 Dec 2004 15:33:31 +0000 Message-Id: <1103297611.15917.184.camel@squizzey.bult.co.uk> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Cc: Linux MTD Subject: Re: JFFS2 mount time List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, On Fri, 2004-12-17 at 06:54 -0600, Josh Boyer wrote: > Hm, ok. An alternative to using the system buffer would be to make > JFFS[23] use a write buffer for those devices. Forgive my ignorance .. but what's the difference between using a write buffer and using the system buffer ? >>From my pov, the system buffer is there, already 100% reliable and somewhat larger than any [potential] write buffer ??? (Given the system buffer uses the underlying block devices read / write routines and the block device emulator will typically sit on a block device such as a hard drive or USB flash key .. [?]) > It's already done on > NAND which has some special handling. The support for ECC'd NOR > probably matches more closely what you'd want to do. Take a look at > wbuf.c. Mmm, after looking at wbuf.c I'm none the wiser as to what it does or how it relates .. > Well, if it's better than the original we can always take yours and > replace what's there. Send it on, performance gains are always > welcome. I'm sure there are others interested in what you've done that > will review the code. I think once I get this FL release out the way I'll have a a more in-depth look at JFFS*. It seems to be written almost exclusively for MTD devices .. which is great .. for MTD devices .. but for block devices and flash (USB for example) presented through a standard interface (SCSI for example) it seems there is scope for a much "thinner" filesystem generic devices with a subset of JFFS's feature set. Gareth.