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=-20.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 8C6E0C6377B for ; Wed, 21 Jul 2021 20:22:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 71BE461244 for ; Wed, 21 Jul 2021 20:22:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240510AbhGUTlY (ORCPT ); Wed, 21 Jul 2021 15:41:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:50126 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240365AbhGUTkx (ORCPT ); Wed, 21 Jul 2021 15:40:53 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C6CFC6135F; Wed, 21 Jul 2021 20:21:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626898889; bh=FfhUhy89/u3Y2WYri9XqTocli/05xvUKwKukL+25oAU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZCpuYZOu/1Bf55Mc+JMKG3ZmEnX2fKIZ0sD4zqLCyXQrcKiYuyEzFT0NRVL3x7pbl FrrRxOV3Si1sMt/OmCKxNL/coyhX5+SNyM9x3nZY6dAuxIljdSHIbW8Vw5wL9B5jqi 064310HAthpcbKQ2CKndvZd8URJDdaYHY2O6Q7iBw12S9n0Pv92tt49/fdl+PLnKWf c71cN/HD2X3dvFx92FtOkBiCPeNECxerWEdZKu4IXqJruhpVGEGxwN7mkPzkU7SZHp a1BxL6GPhCiRXPFNC3lLuegRtHMpBa14cvUOQksBh0BCbBzGU9DUlLE3qZdAUYEf2T 1cUA2MCK0a6vg== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 4651F5C0FA2; Wed, 21 Jul 2021 13:21:29 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, "Paul E. McKenney" , kernel test robot , Rong Chen , Nathan Chancellor Subject: [PATCH rcu 12/18] rcu: Make rcu_gp_init() and rcu_gp_fqs_loop noinline to conserve stack Date: Wed, 21 Jul 2021 13:21:20 -0700 Message-Id: <20210721202127.2129660-12-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20210721202042.GA1472052@paulmck-ThinkPad-P17-Gen-1> References: <20210721202042.GA1472052@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The kbuild test project found an oversized stack frame in rcu_gp_kthread() for some kernel configurations. This oversizing was due to a very large amount of inlining, which is unnecessary due to the fact that this code executes infrequently. This commit therefore marks rcu_gp_init() and rcu_gp_fqs_loop noinline_for_stack to conserve stack space. Reported-by: kernel test robot Tested-by: Rong Chen [ paulmck: noinline_for_stack per Nathan Chancellor. ] Reviewed-by: Nathan Chancellor Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index bc6ccf0ba3b24..e472c78036011 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1739,7 +1739,7 @@ static void rcu_strict_gp_boundary(void *unused) /* * Initialize a new grace period. Return false if no grace period required. */ -static bool rcu_gp_init(void) +static noinline_for_stack bool rcu_gp_init(void) { unsigned long firstseq; unsigned long flags; @@ -1933,7 +1933,7 @@ static void rcu_gp_fqs(bool first_time) /* * Loop doing repeated quiescent-state forcing until the grace period ends. */ -static void rcu_gp_fqs_loop(void) +static noinline_for_stack void rcu_gp_fqs_loop(void) { bool first_gp_fqs; int gf = 0; -- 2.31.1.189.g2e36527f23