From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 26 Mar 2004 18:44:30 +0000 (GMT) Received: from purplechoc.demon.co.uk ([IPv6:::ffff:80.176.224.106]:8064 "EHLO skeleton-jack.localnet") by linux-mips.org with ESMTP id ; Fri, 26 Mar 2004 18:44:29 +0000 Received: from pdh by skeleton-jack.localnet with local (Exim 3.35 #1 (Debian)) id 1B6wIX-0000zx-00; Fri, 26 Mar 2004 18:43:17 +0000 Date: Fri, 26 Mar 2004 18:43:17 +0000 To: Atsushi Nemoto Cc: phorton@bitbox.co.uk, linux-mips@linux-mips.org Subject: Re: missing flush_dcache_page call in 2.4 kernel Message-ID: <20040326184317.GA3661@skeleton-jack> References: <20040325.224229.112629304.nemoto@toshiba-tops.co.jp> <20040325143319.GA873@linux-mips.org> <4062F1A1.9070005@bitbox.co.uk> <20040326.122258.41628012.nemoto@toshiba-tops.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040326.122258.41628012.nemoto@toshiba-tops.co.jp> User-Agent: Mutt/1.3.28i From: Peter Horton 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: 4664 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: pdh@colonel-panic.org Precedence: bulk X-list: linux-mips On Fri, Mar 26, 2004 at 12:22:58PM +0900, Atsushi Nemoto wrote: > > phorton> Looks like it. > > phorton> The fix we're using on Cobalt's at the moment is below > phorton> (required for 2.4.x and 2.6.x). > > phorton> Fixing it this way fixes the problem with both page cache > phorton> pages and swap pages. > > phorton> For more details see the threads "Kernel 2.4.23 on Cobalt > phorton> Qube2 - area of problem" and "Instability / caching problems > phorton> on Qube 2 - solved ?" from December last year. > > Thanks, I agree (maybe I should read ML messages more carefully ...) > > This patch fixes my problem also, thanks, but ... I do not think > r4k_flush_icache_page is a best place to fix since my test program is > not related I-cache at all. > Agreed. The fix went here because this is arch specific code and it's called in exactly the two places where there is a problem. > I'm quite sure that it's a kernel bug and may cause problems if any > PIO block device (PIO ide, ide-cs, mtdblock, etc.) are used on CPUs > which have d-cache aliases (not only MIPS). We need a correct fix ... > True. A proper fix would flush the relevant page after PIO transfers into the page cache / swap pages. Unfortunately this would require a hook in the generic kernel. P.