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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 3D96FC352BE for ; Fri, 17 Apr 2020 12:19:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 16C4C20656 for ; Fri, 17 Apr 2020 12:19:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ca3Nklzb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728751AbgDQMTz (ORCPT ); Fri, 17 Apr 2020 08:19:55 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:57833 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726542AbgDQMTy (ORCPT ); Fri, 17 Apr 2020 08:19:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587125992; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=dAvAY7kidzmNvlsCwdf3voHC0ApsCK/J869Shf1r6TI=; b=ca3NklzbTg0LgFNfxe8HCfGyyVVaNfIYqJDQrPPP3n+Q/OIsMfuBEryC+BIu5U1ygLnqOi uNnXb4VmcJVggzeQpjo7RaNdfp8OF9P/BXjCVb8OtWmDwsQdmYAPmHE5W4xasM7mFhNP4F kPP7lHlubfdVV27XaVmD2f1g1pwzT1Q= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-319-PQ7yjlxiMwCNIvSF8HSRGQ-1; Fri, 17 Apr 2020 08:19:50 -0400 X-MC-Unique: PQ7yjlxiMwCNIvSF8HSRGQ-1 Received: by mail-wr1-f70.google.com with SMTP id j16so871243wrw.20 for ; Fri, 17 Apr 2020 05:19:49 -0700 (PDT) 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; bh=dAvAY7kidzmNvlsCwdf3voHC0ApsCK/J869Shf1r6TI=; b=uYd/+3fr9YHqcmYNt082zca6N1kVNJ3GT4tGv+oxXR+kaSa2ximxVRJXXI7TJd8vkP 3C1MjYwcfKKtRg0rluY+gDbFH3zzY/+wwwJhLcW41hEbFx2fq+vm8etm4Xnq692H4xzL L7qEFwcBlzvRYKXQ8SlwYoDXSz4pFJZWiuRd7V7/qK5V6aPPm2trCAeiesu2y7qj+Uob +Yfinql89ZGxzziNqp4lQEW4je+fJLOLOWB2vdacKoZOaZdlqUuTiLgdX79o1hNLGXlz qkjSGFLEYVuysAxRTrGTMrUjcXLkAnlgYl+uLqECgP9xj2ak/P0VYarbKfv6L35H8KS/ ci9Q== X-Gm-Message-State: AGi0Pua5rBH9kivlziJfnSqMeEIe6hFKoWh9wnJtBv7C0k2YvFHlru38 JkNj3y/IJyP67DVAGwdtCLwtVUk6G8UtYQm247M/4UwM7JNJUp2m/NtVRZ2vI3DgQToNpKSQlzb Up4PU+s2OAP7IRZvbMRFRNshn X-Received: by 2002:adf:f091:: with SMTP id n17mr3614536wro.200.1587125988946; Fri, 17 Apr 2020 05:19:48 -0700 (PDT) X-Google-Smtp-Source: APiQypILmJEGttVpZsTMiKNpTiWWB+ukHgKkmui3YD85EvHFoljJkAHvozhKBbMdGxKfllOHT0icJw== X-Received: by 2002:adf:f091:: with SMTP id n17mr3614500wro.200.1587125988687; Fri, 17 Apr 2020 05:19:48 -0700 (PDT) Received: from localhost.localdomain ([151.29.194.179]) by smtp.gmail.com with ESMTPSA id k14sm32506670wrp.53.2020.04.17.05.19.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Apr 2020 05:19:48 -0700 (PDT) Date: Fri, 17 Apr 2020 14:19:45 +0200 From: Juri Lelli To: Dietmar Eggemann Cc: Valentin Schneider , luca abeni , Ingo Molnar , Peter Zijlstra , Vincent Guittot , Steven Rostedt , Daniel Bristot de Oliveira , Wei Wang , Quentin Perret , Alessio Balsini , Pavan Kondeti , Patrick Bellasi , Morten Rasmussen , Qais Yousef , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/4] sched/deadline: Improve admission control for asymmetric CPU capacities Message-ID: <20200417121945.GM9767@localhost.localdomain> References: <20200408095012.3819-1-dietmar.eggemann@arm.com> <20200408095012.3819-3-dietmar.eggemann@arm.com> <20200408153032.447e098d@nowhere> <31620965-e1e7-6854-ad46-8192ee4b41af@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <31620965-e1e7-6854-ad46-8192ee4b41af@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/04/20 19:29, Dietmar Eggemann wrote: [...] > > Maybe we can do a hybrid. We have rd->span and rd->sum_cpu_capacity and > with the help of an extra per-cpu cpumask we could just Hummm, I like the idea, but > DEFINE_PER_CPU(cpumask_var_t, dl_bw_mask); > > dl_bw_cpus(int i) { This works if calls are always local to the rd we are interested into (argument 'i' isn't used). Are we always doing that? > struct cpumask *cpus = this_cpu_cpumask_var_ptr(dl_bw_mask); > ... > cpumask_and(cpus, rd->span, cpu_active_mask); > > return cpumask_weight(cpus); > } > > and > > dl_bw_capacity(int i) { > > struct cpumask *cpus = this_cpu_cpumask_var_ptr(dl_bw_mask); > ... > cpumask_and(cpus, rd->span, cpu_active_mask); > if (cpumask_equal(cpus, rd->span)) > return rd->sum_cpu_capacity; What if capacities change between invocations (with the same span)? Can that happen? > > for_each_cpu(i, cpus) > cap += capacity_orig_of(i); > > return cap; > } > > So only in cases in which rd->span and cpu_active_mask differ we would > have to sum up again. Thanks, Juri