Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754143Ab0ARLpA (ORCPT ); Mon, 18 Jan 2010 06:45:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751471Ab0ARLpA (ORCPT ); Mon, 18 Jan 2010 06:45:00 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:37256 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752106Ab0ARLo5 (ORCPT ); Mon, 18 Jan 2010 06:44:57 -0500 Subject: Re: [RFC] [PATCH 1/7] User Space Breakpoint Assistance Layer (UBP) From: Peter Zijlstra To: Avi Kivity Cc: ananth@in.ibm.com, Jim Keniston , Srikar Dronamraju , Ingo Molnar , Arnaldo Carvalho de Melo , utrace-devel , Frederic Weisbecker , Masami Hiramatsu , Maneesh Soni , Mark Wielaard , LKML In-Reply-To: <4B543F93.3060509@redhat.com> References: <20100111122521.22050.3654.sendpatchset@srikar.in.ibm.com> <20100111122529.22050.32596.sendpatchset@srikar.in.ibm.com> <1263467289.4244.288.camel@laptop> <1263498366.4875.25.camel@localhost.localdomain> <1263546228.4244.343.camel@laptop> <20100115093831.GC26396@in.ibm.com> <1263549014.4244.374.camel@laptop> <4B53213C.9050303@redhat.com> <1263739939.557.20938.camel@twins> <4B5325CF.5000001@redhat.com> <1263740593.557.20967.camel@twins> <4B53661A.9090907@redhat.com> <1263800752.4283.19.camel@laptop> <4B543F93.3060509@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 18 Jan 2010 12:44:32 +0100 Message-ID: <1263815072.4283.305.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 766 Lines: 17 On Mon, 2010-01-18 at 13:01 +0200, Avi Kivity wrote: > > You've made it clear that you don't like it, but not why. > > The kernel already manages the user's address space (except for > MAP_FIXED which is unreliable unless you've already reserved the address > space). I don't see why adding a vma for debugging is so horrible. Well, the kernel only does what the user (and loader) tell it through mmap(). Other than that we never (except this VDSO thing) inject vmas, and I see no reason to start doing that now. -- 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/