From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from carallon.force9.co.uk ([80.229.37.120] helo=carallon.f9.co.uk) by bombadil.infradead.org with esmtp (Exim 4.68 #1 (Red Hat Linux)) id 1JOtUE-0000H9-B2 for linux-mtd@lists.infradead.org; Tue, 12 Feb 2008 11:39:49 +0000 Received: from [127.0.0.1] by carallon.f9.co.uk (MDaemon PRO v9.6.0) with ESMTP id md50000196491.msg for ; Tue, 12 Feb 2008 11:33:21 +0000 Message-ID: <47B1840D.1010702@carallon.com> Date: Tue, 12 Feb 2008 11:33:33 +0000 From: Will Wagner MIME-Version: 1.0 To: linux-mtd@lists.infradead.org Subject: First access to mounted jffs2 partition is slow Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hello, I have an ARM11 system with a JFFS2 partition in NAND flash. It works but the first time it is accessed after mounting it can be very slow. These are the steps I am performing: # flash_eraseall /dev/mtd4 Erasing 128 Kibyte @ 5fe0000 -- 99 % complete. # time mount /dev/mtdblock4 /flash -t jffs2 real 0m 1.25s user 0m 0.01s sys 0m 0.13s # time ls flash - with an empty filsystem, this takes no time real 0m 0.00s user 0m 0.01s sys 0m 0.00s # cp /sdcard/bigfile flash/ - bigfile is ~8MB # umount /flash # time mount /dev/mtdblock4 /flash -t jffs2 real 0m 2.63s user 0m 0.01s sys 0m 0.50s # time ls flash - first time we do this it takes a long time bigfile real 0m 11.79s user 0m 0.00s sys 0m 0.18s # time ls flash - subsequent reads are fast bigfile real 0m 0.00s user 0m 0.01s sys 0m 0.00s It was my understanding that the only slow step should be mounting the partition when it checks the entire filesystem. Is that correct? Is it normal that the first file operation on the partition is slow and then all others are fast? That the mount is slow is not a problem but would be good if we could make the first access faster even if it means the mount must get slower. This is using Linux 2.6.19.2 with uClibc 0.9.29, busybox 1.9.0 and mtd-utils 1.1.0 Thanks, Will. -- ------------------------------------------------------------------------ Will Wagner will_wagner@carallon.com Senior Project Engineer Office Tel: +44 (0)20 7371 2032 Carallon Ltd, Studio G20, Shepherds Building, Rockley Rd, London W14 0DA ------------------------------------------------------------------------