Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753302Ab0ATKpr (ORCPT ); Wed, 20 Jan 2010 05:45:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753120Ab0ATKpq (ORCPT ); Wed, 20 Jan 2010 05:45:46 -0500 Received: from e28smtp07.in.ibm.com ([122.248.162.7]:45926 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752470Ab0ATKpp (ORCPT ); Wed, 20 Jan 2010 05:45:45 -0500 Date: Wed, 20 Jan 2010 16:15:41 +0530 From: Srikar Dronamraju To: Avi Kivity Cc: Jim Keniston , Pekka Enberg , Peter Zijlstra , ananth@in.ibm.com, Ingo Molnar , Arnaldo Carvalho de Melo , utrace-devel , Frederic Weisbecker , Masami Hiramatsu , Maneesh Soni , Mark Wielaard , LKML Subject: Re: [RFC] [PATCH 1/7] User Space Breakpoint Assistance Layer (UBP) Message-ID: <20100120104541.GB30109@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <84144f021001180413w76a8ca2axb0b9f07ee4dea67e@mail.gmail.com> <4B545146.3080001@redhat.com> <20100118124419.GC1628@linux.vnet.ibm.com> <84144f021001180451k2a84f17x3dc24796fea986c9@mail.gmail.com> <4B5459CA.9060603@redhat.com> <4B545ACF.40203@cs.helsinki.fi> <1263852957.2266.38.camel@localhost.localdomain> <4B556855.6040800@redhat.com> <1263923265.4998.28.camel@localhost.localdomain> <4B56D027.3010808@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <4B56D027.3010808@redhat.com> User-Agent: Mutt/1.5.20 (2009-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1080 Lines: 30 > > > >What does the code in the jumped-to vma do? > > 1. Write a trace entry into shared memory, trap into the kernel on overflow. > 2. Trap if a condition is satisfied (fast watchpoint implementation). > > >Is the instrumentation code > >that corresponds to the uprobe handlers encoded in an ad hoc .so? > > Looks like a good idea, but it doesn't matter much to me. > That looks to be a nice idea. We should certainly look into this possibility. However can we look at this option probably a little later? Our plan was to do one step at a time i.e have the basic uprobes in first and target the booster (i.e jump to the next instruction without the need for single-stepping next). We could look at this option of using jump instead of int3 after we are done with the booster. Hope that's okay. -- Thanks and Regards Srikar -- 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/