From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 447006B0087 for ; Mon, 2 Nov 2009 14:33:56 -0500 (EST) Message-ID: <4AEF3419.1050200@redhat.com> Date: Mon, 02 Nov 2009 21:33:45 +0200 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [PATCH 02/11] Add "handle page fault" PV helper. References: <1257076590-29559-1-git-send-email-gleb@redhat.com> <1257076590-29559-3-git-send-email-gleb@redhat.com> <20091102092214.GB8933@elte.hu> <4AEF2D0A.4070807@redhat.com> In-Reply-To: <4AEF2D0A.4070807@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Rik van Riel Cc: Ingo Molnar , Gleb Natapov , kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "H. Peter Anvin" , Thomas Gleixner List-ID: On 11/02/2009 09:03 PM, Rik van Riel wrote: >> This patch is not acceptable unless it's done cleaner. Currently we >> already have 3 callbacks in do_page_fault() (kmemcheck, mmiotrace, >> notifier), and this adds a fourth one. > > > There's another alternative - add our own exception vector > for async page faults. Not sure if that is warranted though, > especially if we already have other callbacks in do_page_fault() > and we can consolidate them. > We can't add an exception vector since all the existing ones are either taken or reserved. We can try to use an interrupt vector as an exception, but that becomes messy, and I'm not sure hardware will allow us to inject an interrupt when interrupts are disabled. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. -- 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