Received: by 2002:ad5:474a:0:0:0:0:0 with SMTP id i10csp870227imu; Fri, 9 Nov 2018 07:24:38 -0800 (PST) X-Google-Smtp-Source: AJdET5fQieaXz/CNYtAqqwTE2EwBA2rkw+1Rsy64ERNU4T59ANc6TJq3LA73x3epJa9l7AXl3I4J X-Received: by 2002:a17:902:70c9:: with SMTP id l9-v6mr8894816plt.329.1541777078054; Fri, 09 Nov 2018 07:24:38 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1541777078; cv=none; d=google.com; s=arc-20160816; b=dkNC+S2hfBuoJ0CeKgFnLDS/ytZmMJNnKoxUFN+vY6Y3p9t+E5Rpqs6RZUekImPAp/ YcYBEnMJm3rkXjDWMStLabk/vsa9uGcnOW+kIBp59wlTtB1/e5PLw94km7MNZSnsQxzL ad5pfcJ3Q1vLkvLRvByuDriyFOyHlU8xL1pnPrNSEXps7Qa6yiNFfJnAB0k0fcK0YBpA vQk2UfXHe2dTRRqrrMl9pKsQZx/08tPBdpAVVzeecnlPKwxNivydDnuAg/+yIGCEeMzU 9pCYZbV2Yko1nwiHKOq19V9PcjjJKNCblsEk2StTveSW4iCV6OhHniGy9Pd10QY3lM9S cILg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=vom0cEn7WqxIe1R1hoJ0wE2lUJEI+12njykKcOCpJOo=; b=SfAoyIns4Q2JFoGeprZXcy8i9sPnRQLDsPQ8t+SdEVi3PkhY9/7IJuESLpUY6YYtiJ U0WIoN2uozn37i8Zs1zlPd0NRwmqAAD931AXszsReqkpj6NSorQPAY6CJ1vRSWDOFJsB DYk2gMyDuiNQAVJpFC6s15zTjzEg8jOeSeMOktyatYE/LOBWHn14+bQHjvdkeugCjEGy N+LPIYQT5wDLb+Xd9bpJNmaQBa2yueUvS5extYKL60JP/p0WdthFGvFGNei84n2v6K0c LAh62xUwrNY3n3yzG/lykHtYi8FNwokGMITsznTrhw07LvGgt51io3ADfVSr96YXwe4y 8fnQ== 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; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id f5si7481718pgr.411.2018.11.09.07.23.37; Fri, 09 Nov 2018 07:24:38 -0800 (PST) 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; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728204AbeKJBCo (ORCPT + 99 others); Fri, 9 Nov 2018 20:02:44 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55412 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727800AbeKJBCo (ORCPT ); Fri, 9 Nov 2018 20:02:44 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F077E3082142; Fri, 9 Nov 2018 15:21:42 +0000 (UTC) Received: from treble (ovpn-124-61.rdu2.redhat.com [10.10.124.61]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 310D810B034B; Fri, 9 Nov 2018 15:21:41 +0000 (UTC) Date: Fri, 9 Nov 2018 09:21:39 -0600 From: Josh Poimboeuf To: Andy Lutomirski Cc: Ingo Molnar , LKML , X86 ML , Ard Biesheuvel , Steven Rostedt , Peter Zijlstra , Thomas Gleixner , Linus Torvalds , Masami Hiramatsu , Jason Baron , Jiri Kosina , David Laight , Borislav Petkov Subject: Re: [PATCH RFC 0/3] Static calls Message-ID: <20181109152139.zig45f6gp24btfbc@treble> References: <20181109072811.GB86700@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Fri, 09 Nov 2018 15:21:43 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 09, 2018 at 07:16:17AM -0800, Andy Lutomirski wrote: > On Thu, Nov 8, 2018 at 11:28 PM Ingo Molnar wrote: > > > > > > All other usecases are bonus, but it would certainly be interesting to > > investigate the impact of using these APIs for tracing: that too is a > > feature enabled everywhere but utilized only by a small fraction of Linux > > users - so literally every single cycle or instruction saved or hot-path > > shortened is a major win. > > For tracing, we'd want static_call_set_to_nop() or something like that, right? Are we talking about tracepoints? Or ftrace? -- Josh