From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 82815 invoked by alias); 16 Sep 2015 15:03:25 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 82729 invoked by uid 89); 16 Sep 2015 15:03:25 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.6 required=5.0 tests=BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail-wi0-f180.google.com Received: from mail-wi0-f180.google.com (HELO mail-wi0-f180.google.com) (209.85.212.180) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Wed, 16 Sep 2015 15:03:24 +0000 Received: by wicfx3 with SMTP id fx3so74865501wic.0 for ; Wed, 16 Sep 2015 08:03:21 -0700 (PDT) X-Received: by 10.194.184.136 with SMTP id eu8mr24610297wjc.151.1442415801083; Wed, 16 Sep 2015 08:03:21 -0700 (PDT) Received: from E107787-LIN ([195.154.84.196]) by smtp.gmail.com with ESMTPSA id z2sm4982236wij.1.2015.09.16.08.03.19 (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Wed, 16 Sep 2015 08:03:20 -0700 (PDT) From: Yao Qi To: Pedro Alves Cc: Ulrich Weigand , Yao Qi , Pierre Langlois , gdb-patches@sourceware.org, cole945@gmail.com Subject: Re: [PATCH 1/2] [GDBserver] Fix compiling conditional expressions accessing registers References: <20150916115014.0A5EA1DA8@oc7340732750.ibm.com> <55F97479.9070807@redhat.com> Date: Wed, 16 Sep 2015 15:03:00 -0000 In-Reply-To: <55F97479.9070807@redhat.com> (Pedro Alves's message of "Wed, 16 Sep 2015 14:54:01 +0100") Message-ID: <86pp1i1k5l.fsf@gmail.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes X-SW-Source: 2015-09/txt/msg00380.txt.bz2 Pedro Alves writes: >> Not sure whether this is a real performance concern for actual use >> cases though. I don't have any actual measurements ... > > Yes, I was just now reading this, and was going to say the same. > > E.g., the original fast tracepoints code was tuned to avoid as much > work as possible in the condition-fails scenario, when the condition > only accesses a global. That is, e.g., "trace foo if debug_knob =3D=3D 1= ". > I no longer have the numbers captured at the time though. I run tspeed.exp, and it shows this patch slows down fast tracepoint from 29ns to 144ns, so we need to commit Wei-chang's patch instead. --=20 Yao (=E9=BD=90=E5=B0=A7)