Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753186Ab0KZH0y (ORCPT ); Fri, 26 Nov 2010 02:26:54 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:48696 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751046Ab0KZH0x (ORCPT ); Fri, 26 Nov 2010 02:26:53 -0500 Date: Fri, 26 Nov 2010 08:26:21 +0100 From: Ingo Molnar To: Masami Hiramatsu Cc: Rusty Russell , Frederic Weisbecker , Ananth N Mavinakayanahalli , Jason Baron , Mathieu Desnoyers , linux-kernel@vger.kernel.org, 2nddept-manager@sdl.hitachi.co.jp, Masami Hiramatsu , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Peter Zijlstra , Steven Rostedt Subject: Re: [PATCH -tip v4 3/3] kprobes: Support delayed unoptimization Message-ID: <20101126072621.GB19589@elte.hu> References: <20101119100925.16882.34772.stgit@ltc236.sdl.hitachi.co.jp> <20101119100948.16882.24259.stgit@ltc236.sdl.hitachi.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101119100948.16882.24259.stgit@ltc236.sdl.hitachi.co.jp> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1752 Lines: 44 * Masami Hiramatsu wrote: > Unoptimization occurs when a probe is unregistered or disabled, and > is heavy because it recovers instructions by using stop_machine(). > This patch delays unoptimization operations and unoptimize several > probes at once by using text_poke_smp_batch(). > This can avoid unexpected system slowdown coming from stop_machine(). > > Changes in v2: > - Use dynamic allocated buffers and params. > > Signed-off-by: Masami Hiramatsu > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: "H. Peter Anvin" > Cc: x86@kernel.org > Cc: Mathieu Desnoyers > Cc: Peter Zijlstra > Cc: Ananth N Mavinakayanahalli > Cc: Steven Rostedt > Cc: linux-kernel@vger.kernel.org > Cc: Rusty Russell > Cc: Frederic Weisbecker > --- > > arch/x86/include/asm/kprobes.h | 4 > arch/x86/kernel/kprobes.c | 45 ++++ > include/linux/kprobes.h | 2 > kernel/kprobes.c | 434 +++++++++++++++++++++++++++------------- > 4 files changed, 344 insertions(+), 141 deletions(-) Hm, this is a scary big patch with non-trivial effects - it should be broken up as much as possible, into successive, bisectable steps. The end result looks mostly fine - it's just this one huge step of a patch that is dangerous. Thanks, Ingo -- 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/