From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_NEOMUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5EB99C282CC for ; Mon, 11 Feb 2019 08:18:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2E7C420675 for ; Mon, 11 Feb 2019 08:18:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="eOcSch0V" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726358AbfBKISq (ORCPT ); Mon, 11 Feb 2019 03:18:46 -0500 Received: from mail-pl1-f194.google.com ([209.85.214.194]:43626 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725931AbfBKISq (ORCPT ); Mon, 11 Feb 2019 03:18:46 -0500 Received: by mail-pl1-f194.google.com with SMTP id f90so4727119plb.10; Mon, 11 Feb 2019 00:18:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=qHB90A5LkE/SiEu5CM908fsd2TysXNxpX8MCxMMBXHU=; b=eOcSch0Vh5/7WT3fB2QbvHaDD9GqqxqRo730aDAijSAfqUwrieehYnxI4XXoIh1gHT ZUmgJMoDqGtdLEWVT823/ZrcA3wgH2mgYv5Z2uZccx3jWmYsvsRb8gbAM0Ldp32yjskP GNA29FA7wGtbQVqsVxvq1lwozafkOAVAWVFC5bvhCVEhjM1LHDFXvsNh8Iq7OL4qwPGc mwrCJH+qn15no7ow38w8df56FEndlzldCRmVrkd94/idRhQTHw6FPtijExLlUKqDQrAU d3SnGZMqBa26+yahIEpxuF0yza7EmyWRWig6Gsw5t7aCPmnjA08WqI0IQgMDRDVWYBl5 dN5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=qHB90A5LkE/SiEu5CM908fsd2TysXNxpX8MCxMMBXHU=; b=JIiQ3Mz/N7b3x4p1rE0uv/wUJIdLUlgOJfokU41LNqseFd5jM8j9hYytIwrJvjTTTq yq842cUI5hn45bbnjOIcwIgFA0k846myCMTxVwjvaIvHqhvjoOrmnMSkicRF0xr94Bry mDS/Nx1JiZz33AWQyAKHNqHsKqDy4QSTUX21tYTN85ryPQ91G+jUsz1hHGl39wKwEow4 FVQZc1TjQLbSPzWiuncFTpTDvF7/Q+GzxFtO4TavM9yxs/XrsnIOt91vNWL/Rt4X8IzL PAi2PoPPje2JHT+2ru7loA41MbY9EyuIYutpWqazsfzQ2F871D/KKbJ24NlZ7JHUEm4t TmSg== X-Gm-Message-State: AHQUAuZOAPMLtVe+bNIpIbQU8g+iiL3KVMC4sMo0SVopEPqclXaLDM+J a9Y9bDTWC7ncof5mg5PXqJE= X-Google-Smtp-Source: AHgI3IYRrxf/dxjKSMQXzZoKXc2/DjjawvfpWAEs+9SI//ll4nKG7dUC6AxykrpE6Peqr+mLL5EVVQ== X-Received: by 2002:a17:902:b20e:: with SMTP id t14mr36621679plr.128.1549873125405; Mon, 11 Feb 2019 00:18:45 -0800 (PST) Received: from ast-mbp ([2620:10d:c090:180::1:1024]) by smtp.gmail.com with ESMTPSA id 63sm12909740pfy.110.2019.02.11.00.18.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 00:18:44 -0800 (PST) Date: Mon, 11 Feb 2019 00:18:42 -0800 From: Alexei Starovoitov To: Adrian Hunter Cc: Ingo Molnar , Peter Zijlstra , Andi Kleen , Alexander Shishkin , Arnaldo Carvalho de Melo , Jiri Olsa , Song Liu , Daniel Borkmann , Alexei Starovoitov , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [RFC PATCH] perf, bpf: Retain kernel executable code in memory to aid Intel PT tracing Message-ID: <20190211081840.j3vhyp3cffftb6m2@ast-mbp> References: <20190207111901.2399-1-adrian.hunter@intel.com> <20190208232924.bpdjuaqufndigtd4@ast-mbp> <85ebb8e5-97a0-801a-8d5f-bc09a72047bb@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <85ebb8e5-97a0-801a-8d5f-bc09a72047bb@intel.com> User-Agent: NeoMutt/20180223 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Feb 11, 2019 at 09:54:01AM +0200, Adrian Hunter wrote: > > Which is not really a real use-case. .. > > perf analysis with PT becomes inaccurate and main goal > > of retaining accurate instruction info is not achieved. > > For the majority of real use-cases, yes it is. In our fleet not a single server is using Intel PT, yet you're proposing to penalize all of them with shrinker-based JIT freeing? There is no negotiation here. NACK