Received: by 2002:a25:6193:0:0:0:0:0 with SMTP id v141csp3880631ybb; Mon, 23 Mar 2020 09:23:00 -0700 (PDT) X-Google-Smtp-Source: ADFU+vsow3vgSk04Hwe8raQ30OrhW6LiYnbc+hzy2HbreRlwxgitxLVSQlNt1LQ5CB534Wkjeo40 X-Received: by 2002:a9d:2215:: with SMTP id o21mr17942543ota.113.1584980580382; Mon, 23 Mar 2020 09:23:00 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1584980580; cv=none; d=google.com; s=arc-20160816; b=SeNTpN21LZLAMowYtBYbWbmH8izvWCufl5o1FyG3MZlNMaB4Gkg2+qn2jv3IRbuES0 nPPDMZXwqZEZnFWuAvGjnJkwn1FcI7kF2F9Q8H8+1pXgvr+i5bBC6I4Nnrw3nSKcEiBz i7P4hMveLA+HE41TBxRWn0xedFh1/+b6m8zxrk4qZQwdAVhFkwgYhBODq6EIFFPsJ9Ys Ek7wiNI8yeqA/iv898q2VULDUBWkmaSU1L+EY6dlK5V83XPpyDD4VPb/o80u8BC21IUW MVlswsKOBLgLo9Tm+cqpIbU+1iDDP8iOENVUkzG7yivxaA8a9iWf1kGFhh+kapxrRgYI ZxvQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:message-id:date:references :in-reply-to:subject:cc:to:from; bh=tS1DMcYOlbDMNPWNNNlXCUU6ea4E7hUK1uUjBIy1C3w=; b=Au0uxc6jM3mWjywuSzFv1536Xw3FYFyKeUmvwmkMUjVhu7TuuwzMyL1Z6SMN79qlE1 xx7qDIn3v7rfZ5pT2hdijsOrowZxIwg+iPJIEX9CMy4LuuvqxSJkr6msSXIwAFXMWExi /jE7EMBSdB1q6IRiNu8WKG+2NCoTM3SoYKXEXQEOEhKOfF2I25TGcZ6IdcmUCXMHr9vJ 7sU7aA/juRiRfZpZO9PJuhazno0jhd8UaPmO0ce4FDxsZgnyYth9GmNLEo2q8Ft04eGQ Xw8/RQ4suUawSkrOhn7lVHVKiTxq/FIvjOsQbJUsIf9CHnQaYdwIUj1kCDKJaKHuyJsa wBAw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id i15si7252395oib.46.2020.03.23.09.22.39; Mon, 23 Mar 2020 09:23:00 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727357AbgCWQWI (ORCPT + 99 others); Mon, 23 Mar 2020 12:22:08 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:41988 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727067AbgCWQWI (ORCPT ); Mon, 23 Mar 2020 12:22:08 -0400 Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jGPpw-00021O-Na; Mon, 23 Mar 2020 17:22:00 +0100 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id 138461040AA; Mon, 23 Mar 2020 17:22:00 +0100 (CET) From: Thomas Gleixner To: Marcelo Tosatti , Chris Friesen , linux-kernel@vger.kernel.org Cc: Christoph Lameter , Vu Tran , Jim Somerville , Andrew Morton , Frederic Weisbecker , Peter Zijlstra Subject: Re: [PATCH] affine kernel threads to specified cpumask In-Reply-To: <20200323135414.GA28634@fuller.cnet> References: <20200323135414.GA28634@fuller.cnet> Date: Mon, 23 Mar 2020 17:22:00 +0100 Message-ID: <87k13boxcn.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Marcelo, Marcelo Tosatti writes: the subject lacks a prefix and the CC list a few people. > This is a kernel enhancement to configure the cpu affinity of kernel > threads via kernel boot option kthread_cpus=. > > With kthread_cpus specified, the cpumask is immediately applied upon > thread launch. This does not affect kernel threads that specify cpu > and node. > > This allows CPU isolation (that is not allowing certain threads > to execute on certain CPUs) without using the isolcpus= parameter, > making it possible to enable load balancing on such CPUs > during runtime. I'm surely missing some background information, but that sentence does not make any sense to me. Thanks, tglx