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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 26E5CC10F13 for ; Mon, 8 Apr 2019 19:15:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DED4920879 for ; Mon, 8 Apr 2019 19:15:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554750933; bh=R898RYWcfSbMLiskJxSelNaT1b9QJrsjBRQJ9a/G1hM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:In-Reply-To: References:List-ID:From; b=BzoithgK2Du0IuO+/WtumFbOeW/gUul5eB9O4oDGcYFsmyaNZ+e+87WODxo6VjKw6 Y7Dpl9cgwkikeKSPGicQaaVYr/ISCIEiylY8mRQ1FIQIYhx+tBrAk2xKW3BgfvJ+A0 aXZt9DqEKBBamFgAMjd4eTETt+XQVw/HnrWrO2xE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729134AbfDHTPb (ORCPT ); Mon, 8 Apr 2019 15:15:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:45238 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727011AbfDHTO1 (ORCPT ); Mon, 8 Apr 2019 15:14:27 -0400 Received: from tzanussi-mobl.hsd1.il.comcast.net (c-98-220-238-81.hsd1.il.comcast.net [98.220.238.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3604421841; Mon, 8 Apr 2019 19:14:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554750867; bh=R898RYWcfSbMLiskJxSelNaT1b9QJrsjBRQJ9a/G1hM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:In-Reply-To: References:From; b=HFh+kiafDG/mf/W36s1NG89PYymL+GFp0LjgzAvpLl5UhZFUN3P/zvHcHihdltxtU /kDPeX2eiFUEDRgs8x6FxLZYNAtD7zTvpGwgXYVQCfg9QHUV6pQ59CRxM//omd1ZUg r9caF9UQwDgev3y8BisWtkPi3F+FAw9zmho3FaM0= From: Tom Zanussi To: linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org Cc: rostedt@goodmis.org, tglx@linutronix.de, C.Emde@osadl.org, jkacur@redhat.com, bigeasy@linutronix.de, daniel.wagner@siemens.com, julia@ni.com, amartin@nvidia.com Subject: [PATCH 05/13] rtmutex/rwlock: preserve state like a sleeping lock Date: Mon, 8 Apr 2019 14:14:07 -0500 Message-Id: <784bd79865718c40cd2564db00f430ae6ac014da.1554737688.git.tom.zanussi@linux.intel.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14.109-rt58-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior [ Upstream commit 4a1bf9e54a013d55ab156cb462c68054cb52ee2d ] The rwlock is spinning while acquiring a lock. Therefore it must become a sleeping lock on RT and preserve its task state while sleeping and waiting for the lock to become available. Reported-by: Joe Korty Cc: stable-rt@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Tom Zanussi --- kernel/locking/rwlock-rt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/locking/rwlock-rt.c b/kernel/locking/rwlock-rt.c index f2e155b2c4a8..c3b91205161c 100644 --- a/kernel/locking/rwlock-rt.c +++ b/kernel/locking/rwlock-rt.c @@ -128,7 +128,7 @@ void __sched __read_rt_lock(struct rt_rw_lock *lock) * That would put Reader1 behind the writer waiting on * Reader2 to call read_unlock() which might be unbound. */ - rt_mutex_init_waiter(&waiter, false); + rt_mutex_init_waiter(&waiter, true); rt_spin_lock_slowlock_locked(m, &waiter, flags); /* * The slowlock() above is guaranteed to return with the rtmutex is -- 2.14.1