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=-14.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6F9AEC11F64 for ; Mon, 28 Jun 2021 19:57:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4221461CB1 for ; Mon, 28 Jun 2021 19:57:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237169AbhF1UAD (ORCPT ); Mon, 28 Jun 2021 16:00:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53576 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235853AbhF1UAB (ORCPT ); Mon, 28 Jun 2021 16:00:01 -0400 Received: from mail-ed1-x531.google.com (mail-ed1-x531.google.com [IPv6:2a00:1450:4864:20::531]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAB7CC061574 for ; Mon, 28 Jun 2021 12:57:34 -0700 (PDT) Received: by mail-ed1-x531.google.com with SMTP id q14so27725943eds.5 for ; Mon, 28 Jun 2021 12:57:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=E7Mh34xdwjYl+E1G2SeJlr8Q6SqgwT3wSTbDvOU0YJY=; b=UvLOrCLt+VJ6fJ53Lyrp6mIVKpkLmN3g/11/WGbK3TzzfJNJxzfVM9sln0/LNNCOKa IQ9OvnPC76kGNOejtbcYfEPKwlvETp/WgFP9RWiHjIqCLN/k7S8rgLtlLsUT8YhJFIel Y9K/rnAq+Lw9HW7AOlyzqAQN3fEEKaCNdA2gdNIRBYM0Jp+ojRIFFIxX7+QcuY3gPrl0 oTFgXcW/quLkQ5Q4IYP/xQYaf2sTlfx5cBQVwZhe9jq3cH7FpUQX+L+Xngn7DVKeEmXA l8j0VWbi+1w8WRL7u4os6o/pjSaHdTWOzQkWGU1dAyfqmvlDZUk2KuDhgZhJyiaFz0Yl r8+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=E7Mh34xdwjYl+E1G2SeJlr8Q6SqgwT3wSTbDvOU0YJY=; b=DXEPN0S1Xc9ht0NC6aOnRkFkujBq5fnXhU0hP1x8SbVV070pG9bQmuGNvx7ff67q61 gn7e3NWYFwn7epBRzoc6e2Lkd7T5VWbkaAUaFnTYShqB5hXGfq2saU0Ec7x+iSDyGUis 1yV5g+yS+MT4aiJxj7c2WCVLDZ0iIk6Rt1NRx5S3llHe4hiBe/GX48zf3npiScKKKH8q r13eT2/3RoGs1XDpH2q2SGc6Y8MxLkVx8xojG1vwsD64XVYtC+JHiFecasjJup74gMHN rO4uM96+sgmtwrWscCPLIjGqNMgb1hm6+edLHcEaVuKRIS8AFG9vaB2MZdt94dyfQXf8 7JSA== X-Gm-Message-State: AOAM530FqUX82yQGoO3+4NUYN2ObSeVnc4kw6Ymk37wkofpPnVUu+k96 yH5n0qPjZ9FA+VR3johZckk= X-Google-Smtp-Source: ABdhPJytQnkPWReBQtEHlI1ZxsPODXKiCXP1PXhJ7eRkOElwI+IFlrAYQb6Y+cZ3G+vjroRi9j5F2w== X-Received: by 2002:a05:6402:2813:: with SMTP id h19mr34848542ede.39.1624910253482; Mon, 28 Jun 2021 12:57:33 -0700 (PDT) Received: from gmail.com (94-21-131-96.pool.digikabel.hu. [94.21.131.96]) by smtp.gmail.com with ESMTPSA id x17sm10350154edr.88.2021.06.28.12.57.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Jun 2021 12:57:33 -0700 (PDT) Sender: Ingo Molnar Date: Mon, 28 Jun 2021 21:57:31 +0200 From: Ingo Molnar To: Linus Torvalds Cc: Linux Kernel Mailing List , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Mel Gorman , Daniel Bristot de Oliveira , Thomas Gleixner , Andrew Morton Subject: [PATCH] sched/core: Disable CONFIG_SCHED_CORE by default Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Linus Torvalds wrote: > On Sun, Jun 27, 2021 at 11:51 PM Ingo Molnar wrote: > > > > - Add "Core Scheduling" via CONFIG_SCHED_CORE=y, > > Grr. > > Why is this feature "default y"? I see no reason why anybody would > enable it outside of cloud providers, which doesn't argue for it being > on by default. You are completely right, I missed this. Find below the patch to fix it - feel free to apply it directly, will rebase sched/urgent accordingly. Thanks, Ingo =====================> From: Ingo Molnar Date: Mon, 28 Jun 2021 21:55:16 +0200 Subject: [PATCH] sched/core: Disable CONFIG_SCHED_CORE by default This option adds extra overhead to the scheduler, and most users wouldn't want it. Reported-by: Linus Torvalds Signed-off-by: Ingo Molnar --- kernel/Kconfig.preempt | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt index bd7c4147b9a8..3654a92e7e70 100644 --- a/kernel/Kconfig.preempt +++ b/kernel/Kconfig.preempt @@ -102,7 +102,6 @@ config PREEMPT_DYNAMIC config SCHED_CORE bool "Core Scheduling for SMT" - default y depends on SCHED_SMT help This option permits Core Scheduling, a means of coordinated task