From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752971AbdLNOPL (ORCPT ); Thu, 14 Dec 2017 09:15:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:45492 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752642AbdLNOPJ (ORCPT ); Thu, 14 Dec 2017 09:15:09 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B898E218DA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=frederic@kernel.org From: Frederic Weisbecker To: Ingo Molnar Cc: LKML , "Paul E. McKenney" , Peter Zijlstra , Linus Torvalds , Chris Metcalf , John Stultz , Frederic Weisbecker , Thomas Gleixner , Luiz Capitulino , Christoph Lameter , Wanpeng Li , Mike Galbraith , Rik van Riel , kernel test robot Subject: [PATCH 2/3] sched/isolation: Enable CONFIG_CPU_ISOLATION=y by default Date: Thu, 14 Dec 2017 15:14:52 +0100 Message-Id: <1513260893-26616-3-git-send-email-frederic@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1513260893-26616-1-git-send-email-frederic@kernel.org> References: <1513260893-26616-1-git-send-email-frederic@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" The "isolcpus=" boot parameter support was always built-in before we moved the related code under CONFIG_CPU_ISOLATION. Having it disabled by default is very confusing for people accustomed to use this parameter. So enable it by dafault to keep the previous behaviour but keep it optable for those who want to tinify their kernels. Signed-off-by: Frederic Weisbecker Cc: Paul E. McKenney Cc: Thomas Gleixner Cc: Chris Metcalf Cc: Christoph Lameter Cc: Linus Torvalds Cc: Luiz Capitulino Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Rik van Riel Cc: Wanpeng Li Cc: Ingo Molnar Cc: John Stultz --- init/Kconfig | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/init/Kconfig b/init/Kconfig index 2934249..690a381 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -461,10 +461,14 @@ endmenu # "CPU/Task time and stats accounting" config CPU_ISOLATION bool "CPU isolation" + default y help Make sure that CPUs running critical tasks are not disturbed by any source of "noise" such as unbound workqueues, timers, kthreads... - Unbound jobs get offloaded to housekeeping CPUs. + Unbound jobs get offloaded to housekeeping CPUs. This is driven by + the "isolcpus=" boot parameter. + + Say Y if unsure. source "kernel/rcu/Kconfig" -- 2.7.4