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[23.128.96.18]) by mx.google.com with ESMTP id m12si317193ild.137.2021.05.19.11.11.58; Wed, 19 May 2021 11:12:11 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=DMufJIyG; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230012AbhERNk7 (ORCPT + 99 others); Tue, 18 May 2021 09:40:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229575AbhERNk6 (ORCPT ); Tue, 18 May 2021 09:40:58 -0400 Received: from mail-lf1-x12f.google.com (mail-lf1-x12f.google.com [IPv6:2a00:1450:4864:20::12f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 56120C061573 for ; Tue, 18 May 2021 06:39:40 -0700 (PDT) Received: by mail-lf1-x12f.google.com with SMTP id x19so14234150lfa.2 for ; Tue, 18 May 2021 06:39:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=nrf7kNqbVnAq1Hf1uDBaFlAV929R3QrjgqvJW3l17CY=; b=DMufJIyGl+qNFpflK8tU5hLtyEQK9T7KiW3MEpqtY3+36Of1jx9dJuhnl+YfejEiLM hPANf0IEpDtgAouU4WTLfVxIzrpDgnNkLM8E+N91lh0Fh1aq488EttAQrJrj1HMscFkz +wqn4bWB1oOKviRzm0K7jp8TjQf0kurdf+i6UUos208vX+n0yPGMg5JCnZmWfP+bbxuP luJYVWEAtucWfTN+0xCrWWFFCvUNvMZTO1LRA25gSk7j2Zk8SiLZJqwLQvMaf2TtPm8h 7mxwLAQ4r2y+5/oW5f9m6zeQv4kqNrG5hW54jVdCmgqxUDhRic5qJhAJb4+BzLxQH5+C zAoA== 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=nrf7kNqbVnAq1Hf1uDBaFlAV929R3QrjgqvJW3l17CY=; b=m/45ycOMh+ovAovAdDEQAGzxvqJLiP0iLtQ4LGHeVUO07LbuK4RjynLd4IMXydKpOe XCVPnr5q0yLK0QA1joexS1iNd48nJ8f9myPQvcMJabacZv+Ah4+smnfVWv/zxTCzswde pbqk4IN1/yXlA4QUqTeFJTtJNmQTnhx8DnTzj5GhDBF2OaBUGLX0Xm8U0gs1Gi7190QT UNZvh0EmIWgk4hUVueJCRMXy9TXGOQJKtBqfQ6dTE8bQnAhcB26z5kPVV/866CNSdAxH QdgCB39ro1qc69FUm4Djcz4huCeDzDu98mWY+fwnCcnOqvA0We2CMgjU/LvgX+bzLUna WseA== X-Gm-Message-State: AOAM533TT0VZgW6AYlHXX6QqF5wug70t4SWoWcQiiV21Pt/1Sqw5PXMS rQ1B7DCZ/5jTWKs4drnx0wGa/SM5oIBpjogkBwPidg== X-Received: by 2002:a05:6512:22c2:: with SMTP id g2mr4601044lfu.305.1621345178822; Tue, 18 May 2021 06:39:38 -0700 (PDT) MIME-Version: 1.0 References: <1621239831-5870-1-git-send-email-beata.michalska@arm.com> <1621239831-5870-2-git-send-email-beata.michalska@arm.com> In-Reply-To: <1621239831-5870-2-git-send-email-beata.michalska@arm.com> From: Vincent Guittot Date: Tue, 18 May 2021 15:39:27 +0200 Message-ID: Subject: Re: [PATCH v4 1/3] sched/core: Introduce SD_ASYM_CPUCAPACITY_FULL sched_domain flag To: Beata Michalska Cc: linux-kernel , Peter Zijlstra , Ingo Molnar , Juri Lelli , Valentin Schneider , Dietmar Eggemann , "corbet@lwn.net" , Randy Dunlap , Linux Doc Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 17 May 2021 at 10:24, Beata Michalska wrote: > > Introducing new, complementary to SD_ASYM_CPUCAPACITY, sched_domain > topology flag, to distinguish between shed_domains where any CPU > capacity asymmetry is detected (SD_ASYM_CPUCAPACITY) and ones where > a full range of CPU capacities is visible to all domain members > (SD_ASYM_CPUCAPACITY_FULL). I'm not sure about what you want to detect: Is it a sched_domain level with a full range of cpu capacity, i.e. with at least 1 min capacity and 1 max capacity ? or do you want to get at least 1 cpu of each capacity ? > > With the distinction between full and partial CPU capacity asymmetry, > brought in by the newly introduced flag, the scope of the original > SD_ASYM_CPUCAPACITY flag gets shifted, still maintaining the existing > behaviour when one is detected on a given sched domain, allowing > misfit migrations within sched domains that do not observe full range > of CPU capacities but still do have members with different capacity > values. It loses though it's meaning when it comes to the lowest CPU > asymmetry sched_domain level per-cpu pointer, which is to be now > denoted by SD_ASYM_CPUCAPACITY_FULL flag. > > Signed-off-by: Beata Michalska > Reviewed-by: Valentin Schneider > --- > include/linux/sched/sd_flags.h | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/include/linux/sched/sd_flags.h b/include/linux/sched/sd_flags.h > index 34b21e9..57bde66 100644 > --- a/include/linux/sched/sd_flags.h > +++ b/include/linux/sched/sd_flags.h > @@ -91,6 +91,16 @@ SD_FLAG(SD_WAKE_AFFINE, SDF_SHARED_CHILD) > SD_FLAG(SD_ASYM_CPUCAPACITY, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) > > /* > + * Domain members have different CPU capacities spanning all unique CPU > + * capacity values. > + * > + * SHARED_PARENT: Set from the topmost domain down to the first domain where > + * all available CPU capacities are visible > + * NEEDS_GROUPS: Per-CPU capacity is asymmetric between groups. > + */ > +SD_FLAG(SD_ASYM_CPUCAPACITY_FULL, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) > + > +/* > * Domain members share CPU capacity (i.e. SMT) > * > * SHARED_CHILD: Set from the base domain up until spanned CPUs no longer share > -- > 2.7.4 >