Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755314Ab0ASIIU (ORCPT ); Tue, 19 Jan 2010 03:08:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754608Ab0ASIIU (ORCPT ); Tue, 19 Jan 2010 03:08:20 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55727 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753458Ab0ASIIT (ORCPT ); Tue, 19 Jan 2010 03:08:19 -0500 Message-ID: <4B556855.6040800@redhat.com> Date: Tue, 19 Jan 2010 10:07:49 +0200 From: Avi Kivity 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: Jim Keniston CC: Pekka Enberg , Srikar Dronamraju , 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) References: <1263740593.557.20967.camel@twins> <1263800752.4283.19.camel@laptop> <4B543F93.3060509@redhat.com> <1263815072.4283.305.camel@laptop> <4B544D7C.2060708@redhat.com> <1263816396.4283.361.camel@laptop> <4B544F8E.1080603@redhat.com> <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> In-Reply-To: <1263852957.2266.38.camel@localhost.localdomain> 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 Content-Length: 998 Lines: 27 On 01/19/2010 12:15 AM, Jim Keniston wrote: > >> I don't like the idea but if the performance benefits are real (are >> they?), >> > Based on what seems to be the closest thing to an apples-to-apples > comparison -- counting the number of calls to a specified function -- > uprobes is 6-7 times faster than the ptrace-based equivalent, ltrace -c. > And of course, uprobes provides much, much more flexibility, appears to > scale better, and works with multithreaded apps. > > Likewise, FWIW, utrace is more than 10x faster than strace -c in > counting system calls. > > This is still with a kernel entry, yes? Do you have plans for a variant that's completely in userspace? -- error compiling committee.c: too many arguments to function -- 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/