Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758115AbYK0K57 (ORCPT ); Thu, 27 Nov 2008 05:57:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753534AbYK0KqH (ORCPT ); Thu, 27 Nov 2008 05:46:07 -0500 Received: from one.firstfloor.org ([213.235.205.2]:48912 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756800AbYK0KqF (ORCPT ); Thu, 27 Nov 2008 05:46:05 -0500 Date: Thu, 27 Nov 2008 11:56:35 +0100 From: Andi Kleen To: Avi Kivity Cc: "H. Peter Anvin" , Alexander van Heukelum , lguest@ozlabs.org, jeremy@xensource.com, LKML , Mike Travis , Cyrill Gorcunov , Steven Rostedt , Andi Kleen , Ingo Molnar , Alexander van Heukelum , Thomas Gleixner Subject: Re: [Lguest] [PATCH RFC/RFB] x86_64, i386: interrupt dispatch changes Message-ID: <20081127105635.GG6703@one.firstfloor.org> References: <20081104122839.GA22864@mailshack.com> <20081104150729.GC21470@localhost> <20081104170501.GE29626@one.firstfloor.org> <1225822006.21441.1282961299@webmail.messagingengine.com> <20081104204400.GC10825@elte.hu> <1226243805.27361.1283784629@webmail.messagingengine.com> <49178E89.2000307@zytor.com> <492DC13F.8020009@redhat.com> <492DE3EF.8060507@zytor.com> <492E72D7.9060201@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <492E72D7.9060201@redhat.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1009 Lines: 31 On Thu, Nov 27, 2008 at 12:13:43PM +0200, Avi Kivity wrote: > H. Peter Anvin wrote: > > > >>I suspect we could get it down to three bytes, by sharing the last > >>byte of the four-byte call sequence with the first byte of the next: > >> > >> 66 e8 ff 66 e8 fc 66 e8 f9 66 e8 f6 ... > >> > >>Every three bytes a new stub begins; it's a four-byte call to offset > >>0x6703 relative to the beginning of the first stub. > >> > >>Can anyone better 24 bits/stub? > > > >On the entirely silly level... > > > >CC xx > > Nice. Can actually go to zero, by pointing the IDT at (unmapped_area + > vector), and deducing the vector in the page fault handler from cr2. That would be still one byte, otherwise you wouldn't get a unique index. -Andi -- ak@linux.intel.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/