From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-fx0-f48.google.com ([209.85.161.48]) by canuck.infradead.org with esmtp (Exim 4.72 #1 (Red Hat Linux)) id 1PVPv1-0001CG-IM for linux-mtd@lists.infradead.org; Wed, 22 Dec 2010 14:43:56 +0000 Received: by fxm2 with SMTP id 2so5664657fxm.21 for ; Wed, 22 Dec 2010 06:43:54 -0800 (PST) Subject: Re: Huge ubi or ubifs sync slowdown since 2.6.32 From: Artem Bityutskiy To: Charles Manning In-Reply-To: <201012211136.22254.manningc2@actrix.gen.nz> References: <201012211136.22254.manningc2@actrix.gen.nz> Content-Type: text/plain; charset="UTF-8" Date: Wed, 22 Dec 2010 16:43:12 +0200 Message-ID: <1293028992.12773.18.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: linux-omap@vger.kernel.org, linux-mtd@lists.infradead.org Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 2010-12-21 at 11:36 +1300, Charles Manning wrote: > Hi All > > I've been looking into a ubifs performance regression on linux-omap 2.6.37. > > My test is pretty simple, copy a 2Mbyte file and sync. > > # sync; date; cp 2Mbyte-file foo; sync; date > > On 2.6.32 and earler, the time between the two dates was around 3 seconds. > On linux-omap master it is around 14 seconds. Ouch! > > At first I thought the problem was due to changes in the OMAP nand drivers, > but raw randwrite speed is actually a bit faster. This suggest the finger > should be pointed at ubi or ubifs. > > I then thought that perhaps the layout of my ubinized image might be a > contributing factor so I erased the partition, ubiformatted and ubimkvoled. > The problem persisted, > > Any suggestions as to what might be broken or how to debug this deeper? 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. -- Best Regards, Artem Bityutskiy (Артём Битюцкий) 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