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=-3.9 required=3.0 tests=BAYES_00,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 AD2B2C4363D for ; Tue, 6 Oct 2020 13:50:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FEDB207EA for ; Tue, 6 Oct 2020 13:50:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="OnsvslPR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726064AbgJFNum (ORCPT ); Tue, 6 Oct 2020 09:50:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57910 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725902AbgJFNul (ORCPT ); Tue, 6 Oct 2020 09:50:41 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A9D4EC061755 for ; Tue, 6 Oct 2020 06:50:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=HWSicsUkOLd+NrAhxw/4TTPErnmmPc99/9X07B2SMTc=; b=OnsvslPRyYU8NFZbHXgNmUgXKL odLPfnAdz6bGAJi/f1h3twz3m+ASB22bNaLvEva9i0G7CnQDoyx1pScZ86BIUnFL5ItGsE/kljy7E yDTRIEIqHbw+/3NdjqUXm6AgKSQDDh7yejmvhDbg18tuZ9ZeLhylnKGpI7NgoTOLs8/BznlJeVZOR UOkuAtsFY/TCb1/tddGL3viKvO2AHwD+4CZ7e8Ou+1mFp3clh2PyCtEARGMCTNzekJhOePkWeqlcG uMHnOpmoAKJgdhO1E8vyO9PFQvX1E57WcwxYJPsymjg91OOVNcjwO5SWUu41V2ymumc67Hn1jUvBF CCZsOyrw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kPnMI-00039k-Nf; Tue, 06 Oct 2020 13:50:27 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id B4F673011C6; Tue, 6 Oct 2020 15:50:25 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id A6F732B82AF21; Tue, 6 Oct 2020 15:50:25 +0200 (CEST) Date: Tue, 6 Oct 2020 15:50:25 +0200 From: Peter Zijlstra To: Steven Rostedt Cc: tglx@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org, bigeasy@linutronix.de, qais.yousef@arm.com, swood@redhat.com, valentin.schneider@arm.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vincent.donnefort@arm.com, tj@kernel.org Subject: Re: [PATCH -v2 15/17] sched: Fix migrate_disable() vs rt/dl balancing Message-ID: <20201006135025.GW2628@hirez.programming.kicks-ass.net> References: <20201005145717.346020688@infradead.org> <20201005150922.458081448@infradead.org> <20201006075939.GL2628@hirez.programming.kicks-ass.net> <20201006094445.09c8b3b9@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201006094445.09c8b3b9@gandalf.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 06, 2020 at 09:44:45AM -0400, Steven Rostedt wrote: > As I've always said. When dealing with real-time systems, you need to be > careful about how you organize your tasks. Ideally, any RT task that is > pinned to a CPU shouldn't be sharing that CPU with anything else that may > be critical. Due to locks we're always sharing.. :-)