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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 2C837C7618F for ; Fri, 19 Jul 2019 21:51:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F129A21882 for ; Fri, 19 Jul 2019 21:51:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389218AbfGSVvB (ORCPT ); Fri, 19 Jul 2019 17:51:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:51034 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388719AbfGSVt6 (ORCPT ); Fri, 19 Jul 2019 17:49:58 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CBA8521897; Fri, 19 Jul 2019 21:49:57 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.92) (envelope-from ) id 1hoalI-00081F-Tg; Fri, 19 Jul 2019 17:49:56 -0400 Message-Id: <20190719214956.816542002@goodmis.org> User-Agent: quilt/0.65 Date: Fri, 19 Jul 2019 17:49:36 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-rt-users Cc: Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Paul Gortmaker , Julia Cartwright , Daniel Wagner , tom.zanussi@linux.intel.com Subject: [PATCH RT 05/16] rcu: Dont allow to change rcu_normal_after_boot on RT References: <20190719214931.700049248@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19.59-rt24-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior [ Upstream commit c6c058c10577815a2491ce661876cff00a4c3b15 ] On RT rcu_normal_after_boot is enabled by default. Don't allow to disable it on RT because the "expedited rcu" would introduce latency spikes. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt (VMware) --- kernel/rcu/update.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 16d8dba23329..ed75addd3ccd 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -69,7 +69,9 @@ module_param(rcu_expedited, int, 0); extern int rcu_normal; /* from sysctl */ module_param(rcu_normal, int, 0); static int rcu_normal_after_boot = IS_ENABLED(CONFIG_PREEMPT_RT_FULL); +#ifndef CONFIG_PREEMPT_RT_FULL module_param(rcu_normal_after_boot, int, 0); +#endif #endif /* #ifndef CONFIG_TINY_RCU */ #ifdef CONFIG_DEBUG_LOCK_ALLOC -- 2.20.1