From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755311Ab0ARIiR (ORCPT ); Mon, 18 Jan 2010 03:38:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755197Ab0ARIiK (ORCPT ); Mon, 18 Jan 2010 03:38:10 -0500 Received: from terminus.zytor.com ([198.137.202.10]:45270 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752843Ab0ARIiH (ORCPT ); Mon, 18 Jan 2010 03:38:07 -0500 Message-ID: <4B541D08.9040802@zytor.com> Date: Mon, 18 Jan 2010 00:34:16 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-4.fc12 Thunderbird/3.0 MIME-Version: 1.0 To: Gleb Natapov CC: Peter Zijlstra , kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, avi@redhat.com, mingo@elte.hu, tglx@linutronix.de, riel@redhat.com, cl@linux-foundation.org Subject: Re: [PATCH v3 04/12] Add "handle page fault" PV helper. References: <1262700774-1808-1-git-send-email-gleb@redhat.com> <1262700774-1808-5-git-send-email-gleb@redhat.com> <1263490267.4244.340.camel@laptop> <20100117144411.GI31692@redhat.com> In-Reply-To: <20100117144411.GI31692@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/17/2010 06:44 AM, Gleb Natapov wrote: > On Thu, Jan 14, 2010 at 06:31:07PM +0100, Peter Zijlstra wrote: >> On Tue, 2010-01-05 at 16:12 +0200, Gleb Natapov wrote: >>> Allow paravirtualized guest to do special handling for some page faults. >>> >>> The patch adds one 'if' to do_page_fault() function. The call is patched >>> out when running on physical HW. I ran kernbech on the kernel with and >>> without that additional 'if' and result were rawly the same: >> >> So why not program a different handler address for the #PF/#GP faults >> and avoid the if all together? > I would gladly use fault vector reserved by x86 architecture, but I am > not sure Intel will be happy about it. > That's what it's there for... see Peter Z.'s response. -hpa From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH v3 04/12] Add "handle page fault" PV helper. Date: Mon, 18 Jan 2010 00:34:16 -0800 Message-ID: <4B541D08.9040802@zytor.com> References: <1262700774-1808-1-git-send-email-gleb@redhat.com> <1262700774-1808-5-git-send-email-gleb@redhat.com> <1263490267.4244.340.camel@laptop> <20100117144411.GI31692@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Peter Zijlstra , kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, avi@redhat.com, mingo@elte.hu, tglx@linutronix.de, riel@redhat.com, cl@linux-foundation.org To: Gleb Natapov Return-path: In-Reply-To: <20100117144411.GI31692@redhat.com> Sender: owner-linux-mm@kvack.org List-Id: kvm.vger.kernel.org On 01/17/2010 06:44 AM, Gleb Natapov wrote: > On Thu, Jan 14, 2010 at 06:31:07PM +0100, Peter Zijlstra wrote: >> On Tue, 2010-01-05 at 16:12 +0200, Gleb Natapov wrote: >>> Allow paravirtualized guest to do special handling for some page faults. >>> >>> The patch adds one 'if' to do_page_fault() function. The call is patched >>> out when running on physical HW. I ran kernbech on the kernel with and >>> without that additional 'if' and result were rawly the same: >> >> So why not program a different handler address for the #PF/#GP faults >> and avoid the if all together? > I would gladly use fault vector reserved by x86 architecture, but I am > not sure Intel will be happy about it. > That's what it's there for... see Peter Z.'s response. -hpa -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org