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,URIBL_BLOCKED,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 3EC92C433ED for ; Thu, 8 Apr 2021 22:39:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F0E2E6115B for ; Thu, 8 Apr 2021 22:39:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232909AbhDHWjg (ORCPT ); Thu, 8 Apr 2021 18:39:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:48154 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232918AbhDHWjc (ORCPT ); Thu, 8 Apr 2021 18:39:32 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CC3F06115B; Thu, 8 Apr 2021 22:39:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617921559; bh=z7dimrIBQRXEUVolj+GSg0s9giIVZ5cvdNG3WhkYA8M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dFZSdENtSFfHIH92zu4xby/SCnVj7y+XH0HI2Ai4w4fsAV1ANvKtwrJqqPAk57gZ1 g+F2CSlNcT1hM/QRugucN3qrAEu8GIzO8W11imQYBvyzGUGlIqgD8l/l+PxdJQSx18 aD+SRw0Sf835WAEvyfKnxUxi2xOQenR6v3SPQmwZEVEZ6ciWmhpk2auDraW+qq9FNk Y70W9bdCrkuSCjr/l7vpqAOdbz6HG6Cymf+lAwtdGMK7Ga7dmZZAEkH0Jht9IxDnyB af2dM9Ajq4nNtUdUy+5AUuUniKXoV0hbCZ5QM5+msdfPM/X4mvBfEEsR6NxQLKXuLX PI4wyLH7ipk/Q== 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 5/5] srcu: Early test SRCU polling start Date: Fri, 9 Apr 2021 00:39:02 +0200 Message-Id: <20210408223902.6405-6-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210408223902.6405-1-frederic@kernel.org> References: <20210408223902.6405-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Test early calls to start_poll_synchronize_srcu(), mixed within the early test to call_srcu(), and make sure that poll_state_synchronize_srcu() correctly see the expired grace periods after the srcu_barrier() on late initcall. Normally srcu_barrier() doesn't wait for callback-less grace periods but early calls to start_poll_synchronize_srcu() involve empty callbacks. 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 | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index dd94a602a6d2..7ee57d66a327 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -528,6 +528,7 @@ DEFINE_STATIC_SRCU(early_srcu); struct early_boot_kfree_rcu { struct rcu_head rh; }; +static unsigned long early_cookie[3]; static void early_boot_test_call_rcu(void) { @@ -536,8 +537,14 @@ 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)) { + int i; + early_cookie[0] = start_poll_synchronize_srcu(&early_srcu); call_srcu(&early_srcu, &shead, test_callback); + + for (i = 1; i < ARRAY_SIZE(early_cookie); i++) + early_cookie[i] = start_poll_synchronize_srcu(&early_srcu); + } rhp = kmalloc(sizeof(*rhp), GFP_KERNEL); if (!WARN_ON_ONCE(!rhp)) kfree_rcu(rhp, rh); @@ -561,8 +568,11 @@ static int rcu_verify_early_boot_tests(void) early_boot_test_counter++; rcu_barrier(); if (IS_ENABLED(CONFIG_SRCU)) { + int i; early_boot_test_counter++; srcu_barrier(&early_srcu); + for (i = 0; i < ARRAY_SIZE(early_cookie); i++) + WARN_ON_ONCE(!poll_state_synchronize_srcu(&early_srcu, early_cookie[i])); } } if (rcu_self_test_counter != early_boot_test_counter) { -- 2.25.1