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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 4696AC432BE for ; Wed, 11 Aug 2021 20:14:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 243D760EB5 for ; Wed, 11 Aug 2021 20:14:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231904AbhHKUOn (ORCPT ); Wed, 11 Aug 2021 16:14:43 -0400 Received: from foss.arm.com ([217.140.110.172]:57720 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231897AbhHKUOi (ORCPT ); Wed, 11 Aug 2021 16:14:38 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4DCC11042; Wed, 11 Aug 2021 13:14:14 -0700 (PDT) Received: from e113632-lin.cambridge.arm.com (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 3C7863F40C; Wed, 11 Aug 2021 13:14:11 -0700 (PDT) From: Valentin Schneider To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, rcu@vger.kernel.org, linux-rt-users@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Steven Rostedt , Daniel Bristot de Oliveira , Sebastian Andrzej Siewior , "Paul E. McKenney" , Frederic Weisbecker , Josh Triplett , Mathieu Desnoyers , Davidlohr Bueso , Lai Jiangshan , Joel Fernandes , Anshuman Khandual , Vincenzo Frascino , Steven Price , Ard Biesheuvel , Boqun Feng , Mike Galbraith Subject: [PATCH v3 1/4] rcutorture: Don't disable softirqs with preemption disabled when PREEMPT_RT Date: Wed, 11 Aug 2021 21:13:51 +0100 Message-Id: <20210811201354.1976839-2-valentin.schneider@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210811201354.1976839-1-valentin.schneider@arm.com> References: <20210811201354.1976839-1-valentin.schneider@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Running RCU torture with CONFIG_PREEMPT_RT under v5.14-rc4-rt6 triggers: [ 8.755472] DEBUG_LOCKS_WARN_ON(this_cpu_read(softirq_ctrl.cnt)) [ 8.755482] WARNING: CPU: 1 PID: 137 at kernel/softirq.c:172 __local_bh_disable_ip (kernel/softirq.c:172 (discriminator 31)) [ 8.755500] Modules linked in: [ 8.755506] CPU: 1 PID: 137 Comm: rcu_torture_rea Not tainted 5.14.0-rc4-rt6 #171 [ 8.755514] Hardware name: ARM Juno development board (r0) (DT) [ 8.755518] pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--) [ 8.755622] Call trace: [ 8.755624] __local_bh_disable_ip (kernel/softirq.c:172 (discriminator 31)) [ 8.755633] rcutorture_one_extend (kernel/rcu/rcutorture.c:1453) [ 8.755640] rcu_torture_one_read (kernel/rcu/rcutorture.c:1601 kernel/rcu/rcutorture.c:1645) [ 8.755645] rcu_torture_reader (kernel/rcu/rcutorture.c:1737) [ 8.755650] kthread (kernel/kthread.c:327) [ 8.755656] ret_from_fork (arch/arm64/kernel/entry.S:783) [ 8.755663] irq event stamp: 11959 [ 8.755666] hardirqs last enabled at (11959): __rcu_read_unlock (kernel/rcu/tree_plugin.h:695 kernel/rcu/tree_plugin.h:451) [ 8.755675] hardirqs last disabled at (11958): __rcu_read_unlock (kernel/rcu/tree_plugin.h:661 kernel/rcu/tree_plugin.h:451) [ 8.755683] softirqs last enabled at (11950): __local_bh_enable_ip (./arch/arm64/include/asm/irqflags.h:85 kernel/softirq.c:261) [ 8.755692] softirqs last disabled at (11942): rcutorture_one_extend (./include/linux/bottom_half.h:19 kernel/rcu/rcutorture.c:1441) Per this warning, softirqs cannot be disabled in a non-preemptible region under CONFIG_PREEMPT_RT. Adjust RCU torture accordingly. Signed-off-by: Valentin Schneider --- kernel/rcu/rcutorture.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index eecd1caef71d..4f3db1d3170d 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1548,6 +1548,8 @@ rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp) * them on non-RT. */ if (IS_ENABLED(CONFIG_PREEMPT_RT)) { + /* Can't disable bh in atomic context under PREEMPT_RT */ + mask &= ~(RCUTORTURE_RDR_ATOM_BH | RCUTORTURE_RDR_ATOM_RBH); /* * Can't release the outermost rcu lock in an irq disabled * section without preemption also being disabled, if irqs -- 2.25.1 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=-17.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 C5A56C4338F for ; Wed, 11 Aug 2021 20:17:23 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8FD6460EE2 for ; Wed, 11 Aug 2021 20:17:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 8FD6460EE2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=kt+Fo93smbDlEnpeIqAt9Zhc2W3yT2vhwZfD4zkoUKo=; b=3JIDZEfrPt3WXU +kLPV6cGgyr1AjY4n2bEwqehEFNgdeUpbmn2IYTpXjgTRO4LtjWZSSepnXmf8ZpBBvzYYWhPaM471 IBsQ0zGKX9pmtjWZ5T2O7eB8VZnYuKXNsapT350t0gcir3KDHeM6F9+JxAi2a8xdWK5cVScgU2ZRU H4bTcdj4ZlMMVjvGm3yBkIr0HxKPzMZV39h4f4RfxCRpggsLKkeZtnlg45gs9FKHGTwiqMS/7yS+G ax3QBc1w3L0RCuCUT4IblksQsVIoY2yjzj/rNXuEBtK9gKZ9kt8S1NuTNP4zNpDTteiqofUyfHWl1 Kbx/OohLU+Ew6xEBgtNw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mDucS-00824t-DR; Wed, 11 Aug 2021 20:14:32 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mDucD-0081ye-IA for linux-arm-kernel@lists.infradead.org; Wed, 11 Aug 2021 20:14:19 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4DCC11042; Wed, 11 Aug 2021 13:14:14 -0700 (PDT) Received: from e113632-lin.cambridge.arm.com (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 3C7863F40C; Wed, 11 Aug 2021 13:14:11 -0700 (PDT) From: Valentin Schneider To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, rcu@vger.kernel.org, linux-rt-users@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Steven Rostedt , Daniel Bristot de Oliveira , Sebastian Andrzej Siewior , "Paul E. McKenney" , Frederic Weisbecker , Josh Triplett , Mathieu Desnoyers , Davidlohr Bueso , Lai Jiangshan , Joel Fernandes , Anshuman Khandual , Vincenzo Frascino , Steven Price , Ard Biesheuvel , Boqun Feng , Mike Galbraith Subject: [PATCH v3 1/4] rcutorture: Don't disable softirqs with preemption disabled when PREEMPT_RT Date: Wed, 11 Aug 2021 21:13:51 +0100 Message-Id: <20210811201354.1976839-2-valentin.schneider@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210811201354.1976839-1-valentin.schneider@arm.com> References: <20210811201354.1976839-1-valentin.schneider@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210811_131417_747088_8AF6CF04 X-CRM114-Status: GOOD ( 10.70 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Running RCU torture with CONFIG_PREEMPT_RT under v5.14-rc4-rt6 triggers: [ 8.755472] DEBUG_LOCKS_WARN_ON(this_cpu_read(softirq_ctrl.cnt)) [ 8.755482] WARNING: CPU: 1 PID: 137 at kernel/softirq.c:172 __local_bh_disable_ip (kernel/softirq.c:172 (discriminator 31)) [ 8.755500] Modules linked in: [ 8.755506] CPU: 1 PID: 137 Comm: rcu_torture_rea Not tainted 5.14.0-rc4-rt6 #171 [ 8.755514] Hardware name: ARM Juno development board (r0) (DT) [ 8.755518] pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--) [ 8.755622] Call trace: [ 8.755624] __local_bh_disable_ip (kernel/softirq.c:172 (discriminator 31)) [ 8.755633] rcutorture_one_extend (kernel/rcu/rcutorture.c:1453) [ 8.755640] rcu_torture_one_read (kernel/rcu/rcutorture.c:1601 kernel/rcu/rcutorture.c:1645) [ 8.755645] rcu_torture_reader (kernel/rcu/rcutorture.c:1737) [ 8.755650] kthread (kernel/kthread.c:327) [ 8.755656] ret_from_fork (arch/arm64/kernel/entry.S:783) [ 8.755663] irq event stamp: 11959 [ 8.755666] hardirqs last enabled at (11959): __rcu_read_unlock (kernel/rcu/tree_plugin.h:695 kernel/rcu/tree_plugin.h:451) [ 8.755675] hardirqs last disabled at (11958): __rcu_read_unlock (kernel/rcu/tree_plugin.h:661 kernel/rcu/tree_plugin.h:451) [ 8.755683] softirqs last enabled at (11950): __local_bh_enable_ip (./arch/arm64/include/asm/irqflags.h:85 kernel/softirq.c:261) [ 8.755692] softirqs last disabled at (11942): rcutorture_one_extend (./include/linux/bottom_half.h:19 kernel/rcu/rcutorture.c:1441) Per this warning, softirqs cannot be disabled in a non-preemptible region under CONFIG_PREEMPT_RT. Adjust RCU torture accordingly. Signed-off-by: Valentin Schneider --- kernel/rcu/rcutorture.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index eecd1caef71d..4f3db1d3170d 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1548,6 +1548,8 @@ rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp) * them on non-RT. */ if (IS_ENABLED(CONFIG_PREEMPT_RT)) { + /* Can't disable bh in atomic context under PREEMPT_RT */ + mask &= ~(RCUTORTURE_RDR_ATOM_BH | RCUTORTURE_RDR_ATOM_RBH); /* * Can't release the outermost rcu lock in an irq disabled * section without preemption also being disabled, if irqs -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel