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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 B8187ECE560 for ; Sun, 23 Sep 2018 19:44:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D71A21477 for ; Sun, 23 Sep 2018 19:44:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5D71A21477 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727024AbeIXBnN (ORCPT ); Sun, 23 Sep 2018 21:43:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59826 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726302AbeIXBnN (ORCPT ); Sun, 23 Sep 2018 21:43:13 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1A3B230832C1; Sun, 23 Sep 2018 19:44:36 +0000 (UTC) Received: from krava (ovpn-204-66.brq.redhat.com [10.40.204.66]) by smtp.corp.redhat.com (Postfix) with SMTP id 04A00831AF; Sun, 23 Sep 2018 19:44:32 +0000 (UTC) Date: Sun, 23 Sep 2018 21:44:32 +0200 From: Jiri Olsa To: Namhyung Kim Cc: Jiri Olsa , Arnaldo Carvalho de Melo , lkml , Ingo Molnar , Alexander Shishkin , Peter Zijlstra , Andi Kleen , Alexey Budankov , kernel-team@lge.com Subject: Re: [PATCH 47/48] perf record: Spread maps for --threads option Message-ID: <20180923194432.GH30923@krava> References: <20180913125450.21342-1-jolsa@kernel.org> <20180913125450.21342-48-jolsa@kernel.org> <20180917114048.GF18395@sejong> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180917114048.GF18395@sejong> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Sun, 23 Sep 2018 19:44:37 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 17, 2018 at 08:40:48PM +0900, Namhyung Kim wrote: > On Thu, Sep 13, 2018 at 02:54:49PM +0200, Jiri Olsa wrote: > > Currently we assign all maps to main thread. Adding > > code that spreads maps for --threads option. > > > > For --thread option we create as many threads as there > > are memory maps in evlist, which is the number of CPUs > > in the system or CPUs we monitor. Each thread gets a > > single data mmap to read. > > > > In addition we have also same amount of tracking mmaps > > for auxiliary events which we don't create special thread > > for. Instead we assign the to the main thread, because > > there's not much traffic expected there. > > > > The assignment is visible from --thread-stats output: > > > > pid write poll skip maps (size 20K) > > 1s 9770 144B 1 0 19K 19K 19K 18K 19K > > 9772 0B 1 0 18K > > 9773 0B 1 0 19K > > 9774 0B 1 0 19K > > > > There are 5 maps for thread 9770 (1 data map and 4 auxiliary) > > and one data map for every other thread. Each thread writes > > data to the separate data file. > > Hmm.. not sure it'll work well for large machines with 1000+ cpus. > What about giving each thread a data mmap and a tracking mmap? well currently we store the tracking data in single file, thats why we need just one thread to write them down with the *_time API, we should be able to properly read the tracking data separately for each cpu jirka