From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [66.78.22.109] (helo=host3.hosting4everyone.com ident=root) by pentafluge.infradead.org with esmtp (Exim 3.22 #1 (Red Hat Linux)) id 16QYOZ-0005cQ-00 for ; Tue, 15 Jan 2002 18:33:15 +0000 From: "Christopher Fowler" To: Cam Mayor ,linux MTD mailing list Reply-To: cfowler@outpostsentinel.com Subject: Re: open question on flash speed/app blocking MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Message-Id: Date: Tue, 15 Jan 2002 13:44:03 -0500 Sender: linux-mtd-admin@lists.infradead.org Errors-To: linux-mtd-admin@lists.infradead.org List-Help: List-Post: List-Subscribe: , List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: I've noticed that when I write to a file on my DOC2000 that they bus does not block until the bufffers are flushd. My flashing program issues a sync() before unmounting the flash. I even write a 21kb config to a raw partition. That can take a while too. I'm not sure if there is a way around this. On the DOC2000 you need to use at least a block size of 4096. Since the M-SYS driver reads and writes in those block sizes. Maybe some other people here can talk about this subject. Chris > Hi all, > > We're making an app that periodically writes a persistance file to flash. I > haven't actually gotten a flash file system area working yet on my board, so > i can't test this yet for speed. I know that the results will vary with the > hardware, the filesystem used, and a handful of other factors. I'm assuming > that a write to the flash will be blocking - that is, nothing else will be > allowed to happen on the bus while that function is being performed. > > For a file the size of 32bytes, 1kByte, and 32kBtyes, what kind of blocking > delay might one expect from linux writing to flash for each of those file > sizes? What would be an optimum flash filesystem to use for something like > this? (if there is one) > > cheers, > cam > > ps. i'm using linux 2.4.6-rmk1-rayl1 and 2.4.16-rmk2. I could use the latest > kernel, too, i just haven't gotten around to it. For development purposes, > i'm using a cirrus CDB89712 development board, which has the cs89712 > processor and some Intel 28f320B3 flash on it. > > ______________________________________________________ > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/ > >