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=-19.0 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=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 671EEC433ED for ; Wed, 14 Apr 2021 13:24:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 460436117A for ; Wed, 14 Apr 2021 13:24:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351340AbhDNNY5 (ORCPT ); Wed, 14 Apr 2021 09:24:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:48192 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233255AbhDNNYq (ORCPT ); Wed, 14 Apr 2021 09:24:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 90A936117A; Wed, 14 Apr 2021 13:24:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618406663; bh=wZaZyLSKW3Uw9c3+YybApCz/BWlPreYcnusf3ah75xE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mTLrtVAe0G+S2ZWTmc1GR/0vdQk7iDWHMmsKTFEhYvZqPwbmyDJHPpax/Z7SkXySC 6x/cWIokrcVkFk4P3NA3t18DUnaHoduOKuc6PXc/CXNI0vpsal3aw+3lQTCDU97+vb pHlIlZm2MB2xiRG5SCiooYsycUKk+uxvz1nz6qPVV+LPgQ3JB7kKis9jErWHrzbHgB oKdok5wSQ7hhGz7UQPhbL/Bzo2yD4NPhrjWxNA0tNdjVwkg27tdCnUsMHRqKnKjzED URIyMul3NsUkvfEgKVvv12E5Jy+3svsuqq12mPijrMUvfQqujqs7ldjPSp4ksodBwC BF8stBkayI18g== From: Frederic Weisbecker To: "Paul E . McKenney" Cc: LKML , Frederic Weisbecker , Uladzislau Rezki , Boqun Feng , Lai Jiangshan , Neeraj Upadhyay , Josh Triplett , Joel Fernandes Subject: [PATCH 2/2] srcu: Early test SRCU polling start Date: Wed, 14 Apr 2021 15:24:13 +0200 Message-Id: <20210414132413.98062-3-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210414132413.98062-1-frederic@kernel.org> References: <20210414132413.98062-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Test an early call to start_poll_synchronize_srcu() and place it before the early test to call_srcu() on the same ssp. After the later call to srcu_barrier(), we expect the first grace period completion to be visible by a subsequent call to poll_state_synchronize_srcu(). Report otherwise. Signed-off-by: Frederic Weisbecker Cc: Boqun Feng Cc: Lai Jiangshan Cc: Neeraj Upadhyay Cc: Josh Triplett Cc: Joel Fernandes Cc: Uladzislau Rezki --- kernel/rcu/update.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index dd94a602a6d2..c21b38cc25e9 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -524,6 +524,7 @@ static void test_callback(struct rcu_head *r) } DEFINE_STATIC_SRCU(early_srcu); +static unsigned long early_srcu_cookie; struct early_boot_kfree_rcu { struct rcu_head rh; @@ -536,8 +537,10 @@ static void early_boot_test_call_rcu(void) struct early_boot_kfree_rcu *rhp; call_rcu(&head, test_callback); - if (IS_ENABLED(CONFIG_SRCU)) + if (IS_ENABLED(CONFIG_SRCU)) { + early_srcu_cookie = start_poll_synchronize_srcu(&early_srcu); call_srcu(&early_srcu, &shead, test_callback); + } rhp = kmalloc(sizeof(*rhp), GFP_KERNEL); if (!WARN_ON_ONCE(!rhp)) kfree_rcu(rhp, rh); @@ -563,6 +566,7 @@ static int rcu_verify_early_boot_tests(void) if (IS_ENABLED(CONFIG_SRCU)) { early_boot_test_counter++; srcu_barrier(&early_srcu); + WARN_ON_ONCE(!poll_state_synchronize_srcu(&early_srcu, early_srcu_cookie)); } } if (rcu_self_test_counter != early_boot_test_counter) { -- 2.25.1