From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267958AbUHXPNt (ORCPT ); Tue, 24 Aug 2004 11:13:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267967AbUHXPNt (ORCPT ); Tue, 24 Aug 2004 11:13:49 -0400 Received: from x35.xmailserver.org ([69.30.125.51]:2710 "EHLO x35.xmailserver.org") by vger.kernel.org with ESMTP id S267958AbUHXPNq (ORCPT ); Tue, 24 Aug 2004 11:13:46 -0400 X-AuthUser: davidel@xmailserver.org Date: Tue, 24 Aug 2004 08:13:39 -0700 (PDT) From: Davide Libenzi X-X-Sender: davide@bigblue.dev.mdolabs.com To: Arjan van de Ven cc: Linux Kernel Mailing List , Andy Kleen , Andrew Morton , Linus Torvalds Subject: Re: [patch] lazy TSS's I/O bitmap copy ... In-Reply-To: <1093330271.2792.3.camel@laptop.fenrus.com> Message-ID: References: <1093330271.2792.3.camel@laptop.fenrus.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 24 Aug 2004, Arjan van de Ven wrote: > On Mon, 2004-08-23 at 23:23, Davide Libenzi wrote: > > The following patch implements a lazy I/O bitmap copy for the i386 > > architecture. With I/O bitmaps now reaching considerable sizes, if the > > switched task does not perform any I/O operation, we can save the copy > > altogether. In my box X is working fine with the following patch, even if > > more test would be required. > > the thing is that X will not hit your fault path, since it runs with > iopl() called... your patch is a nice optimisation for X as a result, > however as test, X is almost worthless ;( Arjan, using FC1 here and X definitely hits the GPF path. A few crashes when doing The Wrong Thing confirmed it yesterday :-) Also, according to the snippet Alan posted, X does iopl() on fallback of failing ioperm() IIRC. - Davide