From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261673AbVEPOyV (ORCPT ); Mon, 16 May 2005 10:54:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261670AbVEPOwr (ORCPT ); Mon, 16 May 2005 10:52:47 -0400 Received: from clock-tower.bc.nu ([81.2.110.250]:49375 "EHLO lxorguk.ukuu.org.uk") by vger.kernel.org with ESMTP id S261673AbVEPOwE (ORCPT ); Mon, 16 May 2005 10:52:04 -0400 Subject: Re: Disk write cache (Was: Hyper-Threading Vulnerability) From: Alan Cox To: Mikulas Patocka Cc: Tomasz Torcz , Linux Kernel Mailing List In-Reply-To: References: <1115963481.1723.3.camel@alderaan.trey.hu> <20050513211609.75216bf8.diegocg@gmail.com> <20050515095446.GE68736@muc.de> <20050515141207.GB94354@muc.de> <20050515145241.GA5627@irc.pl> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1116255017.21358.40.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Mon, 16 May 2005 15:50:20 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sul, 2005-05-15 at 16:00, Mikulas Patocka wrote: > There are rumors that some disks ignore FLUSH CACHE command just to get > higher benchmarks in Windows. But I haven't heart of any proof. Does > anybody know, what companies fake this command? The specification was intentionally written so that his command has to do what it is specified to or be unknown and thus error and not be in the ident info. That was done by people who wanted to be very sure that any vendor who tried to shortcut the command would have "sue me" written on their forehead. There are problems with a few older drives which have a write cache but don't support cache commands. Alan