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=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 69D94C433E0 for ; Thu, 13 Aug 2020 01:46:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 439E72184D for ; Thu, 13 Aug 2020 01:46:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726641AbgHMBqC (ORCPT ); Wed, 12 Aug 2020 21:46:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:33196 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726484AbgHMBp5 (ORCPT ); Wed, 12 Aug 2020 21:45:57 -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 164BA2177B; Thu, 13 Aug 2020 01:45:57 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94) (envelope-from ) id 1k62JY-00751e-3P; Wed, 12 Aug 2020 21:45:56 -0400 Message-ID: <20200813014555.980104906@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 12 Aug 2020 21:45:39 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-rt-users Cc: Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Daniel Wagner , Tom Zanussi , "Srivatsa S. Bhat" Subject: [PATCH RT 5/6] rwsem: Provide down_read_non_owner() and up_read_non_owner() for -RT References: <20200813014534.833107526@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org 5.4.54-rt33-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior The rwsem implementation on -RT allows multiple reader and there is no owner tracking anymore. We can provide down_read_non_owner() and up_read_non_owner() by skipping the owner check bits which are only available in the !RT implementation. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt (VMware) --- kernel/locking/rwsem.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 0d11ba11a32a..0325c721f9b3 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -1616,15 +1616,15 @@ void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest) } EXPORT_SYMBOL(_down_write_nest_lock); -#ifndef CONFIG_PREEMPT_RT void down_read_non_owner(struct rw_semaphore *sem) { might_sleep(); __down_read(sem); +#ifndef CONFIG_PREEMPT_RT __rwsem_set_reader_owned(sem, NULL); +#endif } EXPORT_SYMBOL(down_read_non_owner); -#endif void down_write_nested(struct rw_semaphore *sem, int subclass) { @@ -1649,13 +1649,13 @@ int __sched down_write_killable_nested(struct rw_semaphore *sem, int subclass) } EXPORT_SYMBOL(down_write_killable_nested); -#ifndef CONFIG_PREEMPT_RT void up_read_non_owner(struct rw_semaphore *sem) { +#ifndef CONFIG_PREEMPT_RT DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem); +#endif __up_read(sem); } EXPORT_SYMBOL(up_read_non_owner); -#endif #endif -- 2.28.0