Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262048AbVCZLqd (ORCPT ); Sat, 26 Mar 2005 06:46:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262049AbVCZLqd (ORCPT ); Sat, 26 Mar 2005 06:46:33 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:52646 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S262048AbVCZLqY (ORCPT ); Sat, 26 Mar 2005 06:46:24 -0500 Subject: Re: Linux 2.4.30-rc2 From: Arjan van de Ven To: Willy Tarreau Cc: Marcelo Tosatti , linux-kernel@vger.kernel.org, davej@redhat.com In-Reply-To: <20050326113426.GO30052@alpha.home.local> References: <20050326004631.GC17637@logos.cnet> <20050326113426.GO30052@alpha.home.local> Content-Type: text/plain Date: Sat, 26 Mar 2005 12:46:19 +0100 Message-Id: <1111837579.8042.5.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 (2.0.4-2) Content-Transfer-Encoding: 7bit X-Spam-Score: 4.4 (++++) X-Spam-Report: SpamAssassin version 2.63 on pentafluge.infradead.org summary: Content analysis details: (4.4 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.7 RISK_FREE BODY: Risk free. Suuurreeee.... 1.1 RCVD_IN_DSBL RBL: Received via a relay in list.dsbl.org [] 2.5 RCVD_IN_DYNABLOCK RBL: Sent directly from dynamic IP address [80.57.133.107 listed in dnsbl.sorbs.net] 0.1 RCVD_IN_SORBS RBL: SORBS: sender is listed in SORBS [80.57.133.107 listed in dnsbl.sorbs.net] X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 860 Lines: 19 On Sat, 2005-03-26 at 12:34 +0100, Willy Tarreau wrote: > Marcelo, > > just another one and that's all. Zachary Amsden found an unconditional > write to a debug register in the signal delivery path which is only > needed when we use a breakpoint. This is a very expensive operation on > x86, and doing it conditionnaly enhanced signal delivery speed by 33% > for him. this sounds rather risky for this late in the game; heck it sounds risky in 2.4 period. This code changed a lot in 2.6 so just a plain backport is by no means risk free, while the effect of a wrong debug register can even have security impact. - 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/