Received: by 2002:a5b:505:0:0:0:0:0 with SMTP id o5csp7333272ybp; Wed, 16 Oct 2019 07:17:59 -0700 (PDT) X-Google-Smtp-Source: APXvYqypRmjmADmR2LhUtad+vourP6S0wcEm3R4W2ZH43W7MMnDDiWwqX92JdrDPUqHL4PsfChtW X-Received: by 2002:a05:6402:1a3b:: with SMTP id be27mr4923102edb.210.1571235479512; Wed, 16 Oct 2019 07:17:59 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1571235479; cv=none; d=google.com; s=arc-20160816; b=KSd5V4cqZs+0Ry0KZtyy4jLjcsyoSPzShmo2x1S45o8vGDrWcbtdZERqdoaV3oGOkY 9s1ORJr2LymyAYTtoCbUPfuUeaCFHkiJBeiTzQIWGxyJadkDCTcv3SWWT8Tlef7VcBD4 c64cwEn1P7Dd8X6xE18OEkPfixQ4awFy62qEanCGbzx9fno5f0RZvn0saKI9hhfTjzU7 etEJoPrOvd6FCGd2kQjpGFttnSS9XaA2c38dgjXyz5WVZIp3ppLuWs94fjdQqR5N3D2m W0ZXkYwYGS4pqoGPwcCxmxBbDY1xeFOgGGbIaRPEZfJoMxrcO5GDaRHOqsq6nimVxAgS dZrw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:user-agent:references :message-id:in-reply-to:subject:cc:to:from:date; bh=VhsZTKcrORL3v015VP2f3P2r+6QGvwBWpeFP+3kK4Og=; b=Q637wGeoDPrAH57FtWmVGe+7aPyPkg5unoLO12EnmwnUCtigoP9E4/x+VeuqKjlF/K B6MFgh1t2BNg6W/1M8SPVKENZ94PToLcfOoTAadBdKKf41ZMoRWmq/vD0fjOJj1yFVIy 9zHHw3tanms5Q+BbcpVMEN867vlmLgZFajFfRQk6FirMjSJXck4vjbaPXTyofnNSXKE4 E+AXhRPy05r28poYBCy7fb+kZ7t5pbgPUKSmjoa6OlFme7nK5I8IbyUzhDk2mDwj/IZY Rm8EHi2B3OHhfqrKuI/AenCpqLHZVMuuMKr+a2sMCud8R4qXcxvM2reLpVCuAV1714Ak yIgg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id q1si12785189edj.354.2019.10.16.07.17.35; Wed, 16 Oct 2019 07:17:59 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404612AbfJPKPy (ORCPT + 99 others); Wed, 16 Oct 2019 06:15:54 -0400 Received: from mx2.suse.de ([195.135.220.15]:50398 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2404606AbfJPKPx (ORCPT ); Wed, 16 Oct 2019 06:15:53 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E0F3DB266; Wed, 16 Oct 2019 10:15:51 +0000 (UTC) Date: Wed, 16 Oct 2019 12:15:50 +0200 (CEST) From: Miroslav Benes To: Peter Zijlstra cc: Steven Rostedt , Joe Lawrence , Jessica Yu , x86@kernel.org, linux-kernel@vger.kernel.org, mhiramat@kernel.org, bristot@redhat.com, jbaron@akamai.com, torvalds@linux-foundation.org, tglx@linutronix.de, mingo@kernel.org, namit@vmware.com, hpa@zytor.com, luto@kernel.org, ard.biesheuvel@linaro.org, jpoimboe@redhat.com, live-patching@vger.kernel.org Subject: Re: [PATCH v3 5/6] x86/ftrace: Use text_poke() In-Reply-To: <20191016074217.GL2328@hirez.programming.kicks-ass.net> Message-ID: References: <20191010115449.22044b53@gandalf.local.home> <20191010172819.GS2328@hirez.programming.kicks-ass.net> <20191011125903.GN2359@hirez.programming.kicks-ass.net> <20191015130739.GA23565@linux-8ccs> <20191015135634.GK2328@hirez.programming.kicks-ass.net> <88bab814-ea24-ece9-2bc0-7a1e10a62f12@redhat.com> <20191015153120.GA21580@linux-8ccs> <7e9c7dd1-809e-f130-26a3-3d3328477437@redhat.com> <20191015182705.1aeec284@gandalf.local.home> <20191016074217.GL2328@hirez.programming.kicks-ass.net> User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 16 Oct 2019, Peter Zijlstra wrote: > > which are not compatible with livepatching. GCC upstream now has > > -flive-patching option, which disables all those interfering optimizations. > > Which, IIRC, has a significant performance impact and should thus really > not be used... Fortunately, the impact is negligible. Miroslav