From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753228AbeABLNP (ORCPT + 1 other); Tue, 2 Jan 2018 06:13:15 -0500 Received: from laurent.telenet-ops.be ([195.130.137.89]:35598 "EHLO laurent.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751932AbeABLNN (ORCPT ); Tue, 2 Jan 2018 06:13:13 -0500 From: Geert Uytterhoeven To: Frederic Weisbecker , Ingo Molnar Cc: Nicolas Pitre , linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH] sched/isolation: Make CPU_ISOLATION depend on SMP or COMPILE_TEST Date: Tue, 2 Jan 2018 12:13:10 +0100 Message-Id: <1514891590-20782-1-git-send-email-geert@linux-m68k.org> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On uniprocessor systems, critical and non-critical tasks cannot be isolated, as there is only a single CPU core. Hence enabling CPU isolation by default on such systems does not make much sense. Instead of changing the default for !SMP, fix this by making the feature depend on SMP, with an override for compile-testing. Note that its sole selector (NO_HZ_FULL) already depends on SMP. This decreases kernel size for a default uniprocessor kernel by ca. 1 KiB. Fixes: 2c43838c99d9d23f ("sched/isolation: Enable CONFIG_CPU_ISOLATION=y by default") Signed-off-by: Geert Uytterhoeven --- init/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/init/Kconfig b/init/Kconfig index 690a381adee0d164..c1221332e128c700 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -461,6 +461,7 @@ endmenu # "CPU/Task time and stats accounting" config CPU_ISOLATION bool "CPU isolation" + depends on SMP || COMPILE_TEST default y help Make sure that CPUs running critical tasks are not disturbed by -- 2.7.4