From mboxrd@z Thu Jan 1 00:00:00 1970 From: Artem Bityutskiy Subject: Re: Huge ubi or ubifs sync slowdown since 2.6.32 Date: Wed, 22 Dec 2010 16:43:12 +0200 Message-ID: <1293028992.12773.18.camel@localhost> References: <201012211136.22254.manningc2@actrix.gen.nz> Reply-To: dedekind1@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-bw0-f45.google.com ([209.85.214.45]:50082 "EHLO mail-bw0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753110Ab0LVOo1 (ORCPT ); Wed, 22 Dec 2010 09:44:27 -0500 Received: by bwz16 with SMTP id 16so5785319bwz.4 for ; Wed, 22 Dec 2010 06:43:56 -0800 (PST) In-Reply-To: <201012211136.22254.manningc2@actrix.gen.nz> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Charles Manning Cc: linux-mtd@lists.infradead.org, linux-omap@vger.kernel.org On Tue, 2010-12-21 at 11:36 +1300, Charles Manning wrote: > Hi All >=20 > I've been looking into a ubifs performance regression on linux-omap 2= =2E6.37. >=20 > My test is pretty simple, copy a 2Mbyte file and sync. >=20 > # sync; date; cp 2Mbyte-file foo; sync; date >=20 > On 2.6.32 and earler, the time between the two dates was around 3 sec= onds. > On linux-omap master it is around 14 seconds. Ouch! >=20 > At first I thought the problem was due to changes in the OMAP nand dr= ivers,=20 > but raw randwrite speed is actually a bit faster. This suggest the fi= nger=20 > should be pointed at ubi or ubifs. >=20 > I then thought that perhaps the layout of my ubinized image might be = a=20 > contributing factor so I erased the partition, ubiformatted and ubimk= voled.=20 > The problem persisted, >=20 > Any suggestions as to what might be broken or how to debug this deepe= r? Can you try this on nandsim and see if there are still differences? You can make nandsim slower by injecting an udelay somewhere. Try this on your x86 host - this way you'll narrow this down to an OMAP-specific or platform-independent problem. --=20 Best Regards, Artem Bityutskiy (=D0=90=D1=80=D1=82=D1=91=D0=BC =D0=91=D0=B8=D1=82=D1=8E= =D1=86=D0=BA=D0=B8=D0=B9) -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html