From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757942Ab0CCATi (ORCPT ); Tue, 2 Mar 2010 19:19:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60255 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754729Ab0CCATf (ORCPT ); Tue, 2 Mar 2010 19:19:35 -0500 Message-ID: <4B8DAAF2.203@redhat.com> Date: Tue, 02 Mar 2010 19:18:58 -0500 From: Masami Hiramatsu User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.7) Gecko/20100120 Fedora/3.0.1-1.fc11 Thunderbird/3.0.1 MIME-Version: 1.0 To: Mathieu Desnoyers CC: Ingo Molnar , Frederic Weisbecker , Ananth N Mavinakayanahalli , lkml , systemtap , DLE , Jim Keniston , Srikar Dronamraju , Christoph Hellwig , Steven Rostedt , "H. Peter Anvin" , Anders Kaseorg , Tim Abbott , Andi Kleen , Jason Baron Subject: Re: [PATCH -tip v3&10 02/18] kprobes: Introduce generic insn_slot framework References: <20100225133342.6725.26971.stgit@localhost6.localdomain6> <20100225133358.6725.82430.stgit@localhost6.localdomain6> <20100225152130.GB12635@Krystal> <4B8C7E23.1000302@redhat.com> In-Reply-To: <4B8C7E23.1000302@redhat.com> X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Masami Hiramatsu wrote: > Mathieu Desnoyers wrote: >> * Masami Hiramatsu (mhiramat@redhat.com) wrote: >>> Make insn_slot framework support various size slots. >>> Current insn_slot just supports one-size instruction buffer slot. However, >>> kprobes jump optimization needs larger size buffers. >> >> OK, so you end up having one insn slot cache for kprobes and one insn >> slot (eventually) for the static jump patching (which needs larger >> instruction slots than kprobes). That seems like a good way to ensure >> you do not use more memory than necessary. >> >> We could possibly go even further and automatically use the right insn >> slot cache given the size of the instruction entry that must be added (a >> bit like the memory allocator which have different pools for each >> allocation order). > > Sure, that will be simpler interface. > >> Possibly that using the terminology of "memory pools" rather than >> "cache" could be a better fit too. So what this really becomes is an >> instruction slot allocator and garbage collector. > > Ah, right. It would be better to rename kprobe_insn_pool() :) Hmm, I tried it. And finally, I found that this doesn't help to simplify code... Maybe it is better to postpone it until another user needs this feature. Thank you, -- Masami Hiramatsu e-mail: mhiramat@redhat.com