From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 22 Nov 2006 21:58:17 +0000 (GMT) Received: from localhost.localdomain ([127.0.0.1]:4554 "EHLO dl5rb.ham-radio-op.net") by ftp.linux-mips.org with ESMTP id S20039336AbWKVV6N (ORCPT ); Wed, 22 Nov 2006 21:58:13 +0000 Received: from denk.linux-mips.net (denk.linux-mips.net [127.0.0.1]) by dl5rb.ham-radio-op.net (8.13.8/8.13.8) with ESMTP id kAMLw8jw009243; Wed, 22 Nov 2006 21:58:09 GMT Received: (from ralf@localhost) by denk.linux-mips.net (8.13.8/8.13.8/Submit) id kAMLw4Tc009242; Wed, 22 Nov 2006 21:58:04 GMT Date: Wed, 22 Nov 2006 21:58:04 +0000 From: Ralf Baechle To: Trevor Hamm Cc: "'Atsushi Nemoto'" , linux-mips@linux-mips.org Subject: Re: Problems booting Linux 2.6.18.1 on MIPS34K core Message-ID: <20061122215803.GA8819@linux-mips.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.2i Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 13239 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Wed, Nov 22, 2006 at 12:31:10PM -0800, Trevor Hamm wrote: > The source of the problem seems to be with squashfs. When I compare booting a kernel using squashfs to one using cramfs (which always seems to boot successfully on power-up), both are reading the troublesome page from /lib/ld-uClibc.so, and both are calling flush_dcache_page() on this page. But in the case of cramfs, flush_dcache_page() causes an immediate cache flush of that page (mapping_mapped(mapping) in __flush_dcache_page() is returning non-zero), while squashfs just marks the page as dirty and defers the cache flush (mapping_mapped(mapping) is returning zero). I have no idea what causes this difference in behaviour, but right now it appears to be a bug in squashfs rather than the linux-mips kernel. There are a few other potencial and real bugs me and Atsushi have found in squashfs. Guess there is a reason why it's not yet in the kernel ... I'm still waiting for feedback from the squashfs author. Ralf