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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 AC4EDC48BE5 for ; Wed, 16 Jun 2021 11:29:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9297D610CD for ; Wed, 16 Jun 2021 11:29:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232592AbhFPLbv (ORCPT ); Wed, 16 Jun 2021 07:31:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232587AbhFPLbo (ORCPT ); Wed, 16 Jun 2021 07:31:44 -0400 Received: from mail-oi1-x230.google.com (mail-oi1-x230.google.com [IPv6:2607:f8b0:4864:20::230]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3234C061768 for ; Wed, 16 Jun 2021 04:29:37 -0700 (PDT) Received: by mail-oi1-x230.google.com with SMTP id t40so2165236oiw.8 for ; Wed, 16 Jun 2021 04:29:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to:cc; bh=Z1ZFZRyBUAatyI9DAgfkD79GCfmHOfeRzXep8r1QClI=; b=FZPbHPS91cK05sahIJSlFQnw22w/94FmfLmbNBHX3QWBKmqp85anaKi2p5Sl5QNyNR 3xeE7nGVM4CBcdr6MxeIx5vflTH6rsoX6ToxrLoAfEc8av8YfeYHtRV37pGO8QxWd5YH 1uikowbFpzQyXO3dYGjWOjXeVW1slyTBs/S29T0CgSCUphatI6hlUNssZc6cawvK7kFX vKISdX/FbsVPkX0jlQLDwoZtZnrZS3qi12RfGpzU5psqd/Ks/GO78t1e+Kx5f6TlkVqB OZ/odUYExkDiRvVQqbH1O6Cgkn7djUMS/pRhsHdUuSMOqIyzvfK1iE/GAgygx9oYHwbu T8fA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=Z1ZFZRyBUAatyI9DAgfkD79GCfmHOfeRzXep8r1QClI=; b=VntNo/7FXBsshBdUcjATV3QH6kV9m0KV8Pg+14FzLgcpT6ch3byaVSu1h0zmdh6VcL ihknKwHB0k7J9b9NtjjnqDFOoHtJp08VtCEorBJgBxwG1/mdr3aZeqOSQuWB7Q/GlhNa FUlLmT44XVoPb1kwkeTkxhvfCuXAyIK2yHqkqXbiwfUKbQ9OxvYnYG66OhcHqX5MG+Zx RXyylsIrafbUVdsv4ztAdMRmAFFViW+5iEFPzcCkN+gtQlqUq2xC5POF9IVdMqBdHUx0 lhu0mYiWT7ewfXvdq2GFev4RhMRe5Fze8RfJBGRqwz2nSh/4xiGJmAZIfkZx7qSDZQXh LMUw== X-Gm-Message-State: AOAM5325CMSWnBBHY/V9tkkB57bzhdFOZnCT77T4EcHE63jLgmURd86D CO2sCL6hP0szKzMrFnQFHmPzFD4eWm8c0Ty0Z3xhlnPkOHQhkg== X-Google-Smtp-Source: ABdhPJy8O7G9/+Z3OtNWZOc2wLQoCcQCTHNRazTnbgep4x7xZPcFbU+PG5jTmK0oa7ukaI6nQZRnsGtoEqrxT2coZ9A= X-Received: by 2002:aca:f5d6:: with SMTP id t205mr2874750oih.58.1623842977245; Wed, 16 Jun 2021 04:29:37 -0700 (PDT) MIME-Version: 1.0 From: Ley Foon Tan Date: Wed, 16 Jun 2021 19:29:26 +0800 Message-ID: Subject: sched: Question about big and little cores system with SMP and EAS To: Vincent Guittot , Ingo Molnar , Peter Zijlstra , Quentin Perret , Greg KH , Dietmar Eggemann Cc: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all Would like to ask the experts here regarding the Symmetric Multi-Processing mode (SMP) with Energy aware scheduler (EAS) support on the big + little cores system. Hardware system: Big and little cores have almost the same ISA, but the big core has some extension instructions that little core doesn't have. With this hardware system, is it still possible to use SMP with EAS? Any suggestions supporting this kind of hardware system in Linux? Thanks in advance. Regards Ley Foon