From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [64.47.34.180] (helo=minotaur.hekimian.com) by canuck.infradead.org with esmtp (Exim 4.43 #1 (Red Hat Linux)) id 1D4Ggd-0005bX-AY for linux-mtd@lists.infradead.org; Thu, 24 Feb 2005 05:57:40 -0500 Message-ID: <421DB31B.7000900@users.sourceforge.net> Date: Thu, 24 Feb 2005 05:57:31 -0500 From: Vern Sauder MIME-Version: 1.0 To: linux-mtd@lists.infradead.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: JFFS2 stats Reply-To: vsauder@users.sourceforge.net List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hello all, I am working on a "failed" PPC system with a 2.4.25 kernel. I saw a lockup where the JFFS2 GC took all the CPU time and the application was hung. All writes to the file system failed causing catastrophic problems. On the way to fixing the application to not completely choke and go haywire, I updated the MTD and JFFS2 drivers to the snapshot as of 16 Feb and now I am having different problems. One thing was that the patch did not apply cleanly; I had to modify several files to fit it into my kernel. I noticed that the mtd driver seems much faster (writes) which was one of my main goal. I was testing the FLASH to verify that the lockup wasn't the MTD failing to write to the FLASH. There were several instances on the FLASH that seemed to show a one bit difference (always a zero that should have been a one). The new drivers sped up the testing. I fixed some utilities/scripts I was using and it looks like the FLASH is writing and reading fine now. I seem to have lost ZLIB compression. It is enabled but the JFFS2 debug says it doesn't know anything about compression 6. It fails to mount it as the root fs but it will mount it later but the data is not right then. I thought I saw somewhere that there was a /proc entry that showed the jffs2 compressors currently loaded. I can't find it now. Is the JFFS2_PROC meaningless for the time being? I am ultimately looking for complete stats on the JFFS2 to tell what is going on in terms of fragmentation and GC. Our application may be overloading the JFFS2 by writing too fast or something like that. I accidentally found significant info from the U-Boot prompt that looks at first glance like it is a good start. Does anyone else have such a tool? Is it in JFFS2 and I haven't found it yet? Vern