From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from wf-out-1314.google.com ([209.85.200.169]) by bombadil.infradead.org with esmtp (Exim 4.69 #1 (Red Hat Linux)) id 1M4Kmi-0006hz-Tt for linux-mtd@lists.infradead.org; Wed, 13 May 2009 20:10:43 +0000 Received: by wf-out-1314.google.com with SMTP id 23so515251wfg.24 for ; Wed, 13 May 2009 13:10:30 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <72795ccb0905130803y25acae9bwde94ed86d0dbb4f2@mail.gmail.com> References: <72795ccb0905060026q7dcb45c0u15c35943374fcc78@mail.gmail.com> <1241673722.27549.14.camel@localhost.localdomain> <1241674092.27549.16.camel@localhost.localdomain> <72795ccb0905130803y25acae9bwde94ed86d0dbb4f2@mail.gmail.com> Date: Wed, 13 May 2009 22:10:30 +0200 Message-ID: <71cd59b00905131310u7d374ddds82da975781f2d00b@mail.gmail.com> Subject: Re: Load UBI faster From: Corentin Chary To: simon polette Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: linux-mtd@lists.infradead.org, spolette@adetelgroup.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 2009/5/13 simon polette : > My NAND is 256MB but I use only a 130MB partition for UBI/UBIFS. > So I implemented the on-flash BBT, that made me save 120ms which is a > sizeable improvement. > On the other hand, skipping crc calculation for header doesn't seem to > save much time (perhaps ~10ms so it's difficult to measure the > difference). You can try playing with bootchart http://www.bootchart.org/ to be sure that there is nothing else to change during the boot process. You can also try to get separate results to see what's taking time (mtd, ubi, ubifs). CONFIG_FUNCTION_TRACER and CONFIG_BOOT_TRACER may help you with that. I'll do some test on the same hardware soon, maybe I'll be able to help you more. -- Corentin Chary http://xf.iksaif.net - http://uffs.org