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=BAYES_00,DATE_IN_PAST_12_24, DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 8C8A4C4363A for ; Wed, 28 Oct 2020 22:44:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 346E82072C for ; Wed, 28 Oct 2020 22:44:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603925082; bh=ouk2B3f956USO9dN7fts9XSFhJT38nVMsOk/r66i1Vs=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=USpJDVaADQvlnpNEg1lF3QZAhSYqAWypEWhzAiuUwJqZWB1wmLOp+v/T10jqkYqzk ygrVNQEOggceqUKwQAJYFWV5mP+Kp85n+g3u9RacqwzH+qLjwSuju+mxYmZj95qqDQ 6CqmfYIasFHnkedS2kZLLxxpaAjCho1uCxGVyhbc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389171AbgJ1Woc (ORCPT ); Wed, 28 Oct 2020 18:44:32 -0400 Received: from mail-ed1-f66.google.com ([209.85.208.66]:41078 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388264AbgJ1Wmh (ORCPT ); Wed, 28 Oct 2020 18:42:37 -0400 Received: by mail-ed1-f66.google.com with SMTP id l24so1150851edj.8 for ; Wed, 28 Oct 2020 15:42:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=9nTu8HSZPYQi/ur9eY3P0aVQ8opJHrdSYJq3buXy8FI=; b=i3SUBDTEj2cYN+cn9ZwsnzmU5zfnF6RYGr83PDJsKs+BxH8bhNULJ2orAbl9aZ23md qsRmDcMXI1CgdwN8mY2C8kLmhQ4VLc8kBnFl3YHBdyNImeEQ23pozB6ND2BRIKZBdzP5 XNjsh/aTx4Gda7Lsj/qsRSPsz+Au2st1+BFKvaLm+ugXDxZoMe2uZlbNHepUAcQLNCsp 81KWkHpURKr4jaHAhRiWu7AYO6SDtuLEckz3RC4Y/r0yKlKmaAjb9CiAMCrO0U8fUurI dG9O/K85UNX45n3xLF6GkDMcEZ9bTXLAJbXGXmpG4zk3qTwyfY3fRTWV8lZt42ZWfNLB cqFQ== X-Gm-Message-State: AOAM532CePqiNI58RB31TDwFAuvKw/Yj8CxobgXdTMPo0o6aOzidpzU3 VAzkKizWtgyafjQ8L4jrH1mL08oqKgxN8kfV+va8AWEg X-Google-Smtp-Source: ABdhPJy08Z73TPw2xMg74bnTFF5RuTnoAMnLfECxeI6k0XGNzXFqgjjeZkL6uadJS+9aIKFbaT0dM7akQjVI2e98JNk= X-Received: by 2002:adf:a553:: with SMTP id j19mr6978128wrb.349.1603868911044; Wed, 28 Oct 2020 00:08:31 -0700 (PDT) MIME-Version: 1.0 References: <1ec29ed6-0047-d22f-630b-a7f5ccee96b4@linux.intel.com> <20201024154309.GA2589351@krava> <01bad2c4-4188-f5f5-452e-a0ea0672a187@linux.intel.com> <20201027121013.GE2900849@krava> <9c76b415-2610-14f8-37d4-461d0d5c078b@linux.intel.com> In-Reply-To: <9c76b415-2610-14f8-37d4-461d0d5c078b@linux.intel.com> From: Namhyung Kim Date: Wed, 28 Oct 2020 16:08:20 +0900 Message-ID: Subject: Re: [PATCH v2 00/15] Introduce threaded trace streaming for basic perf record operation To: Alexey Budankov Cc: Jiri Olsa , Arnaldo Carvalho de Melo , Alexander Shishkin , Adrian Hunter , Andi Kleen , Peter Zijlstra , Ingo Molnar , linux-kernel Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Wed, Oct 28, 2020 at 1:02 AM Alexey Budankov wrote: > > > On 27.10.2020 15:10, Jiri Olsa wrote: > > On Mon, Oct 26, 2020 at 08:59:01PM +0300, Alexey Budankov wrote: > >> > >> On 24.10.2020 18:43, Jiri Olsa wrote: > >>> On Wed, Oct 21, 2020 at 06:52:43PM +0300, Alexey Budankov wrote: > >>>> > >>>> Changes in v2: > >>>> - explicitly added credit tags to patches 6/15 and 15/15, > >>>> additionally to cites [1], [2] > >>>> - updated description of 3/15 to explicitly mention the reason > >>>> to open data directories in read access mode (e.g. for perf report) > >>>> - implemented fix for compilation error of 2/15 > >>>> - explicitly elaborated on found issues to be resolved for > >>>> threaded AUX trace capture > >>>> > >>>> v1: https://lore.kernel.org/lkml/810f3a69-0004-9dff-a911-b7ff97220ae0@linux.intel.com/ > >>>> > >>>> Patch set provides threaded trace streaming for base perf record > >>>> operation. Provided streaming mode (--threads) mitigates profiling > >>>> data losses and resolves scalability issues of serial and asynchronous > >>>> (--aio) trace streaming modes on multicore server systems. The patch > >>>> set is based on the prototype [1], [2] and the most closely relates > >>>> to mode 3) "mode that creates thread for every monitored memory map". > >>> > >>> so what I liked about the previous code was that you could > >>> configure how the threads would be created > >>> > >>> default --threads options created thread for each cpu like > >>> in your change: > >>> > >>> $ perf record -v --threads ... > >>> ... > >>> thread 0 monitor: 0 allowed: 0 > >>> thread 1 monitor: 1 allowed: 1 > >>> thread 2 monitor: 2 allowed: 2 > >>> thread 3 monitor: 3 allowed: 3 > >>> thread 4 monitor: 4 allowed: 4 > >>> thread 5 monitor: 5 allowed: 5 > >>> thread 6 monitor: 6 allowed: 6 > >>> thread 7 monitor: 7 allowed: 7 > >> > >> Yes, it is configurable in the prototype. Even though this patch set > >> doesn't implement that parameters for --thread option, just because > >> VTune doesn't have use cases for that yet, it has still been designed > >> and implemented with that possible extension in mind so it could then > >> be easily added on top of it. > > > > I'm not sure about vtune extensions, but if we are going to > > have --threads option I believe we should make it configurable > > at least to the extend descibed below > > It employs --threads mode only and there are no use cases > observed so far beyond this mode. Do you have or see such > use cases? I don't know about vtune and other users, but it's an important feature for better performance so I agree with Jiri's opinion to make it flexible for the system requirement. Thanks Namhyung