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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 38A9EC4742C for ; Thu, 5 Nov 2020 23:49:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DEA5A2073A for ; Thu, 5 Nov 2020 23:49:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604620146; bh=oUwhdbK9KSe3gQBR4CXLgvIUkHvmer6tKhM7vfbOvtw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AcSES5jxm+aUabdvG9G7LQjkt8/jjHPr4e9tAB479+MgVQeiL6ZpB7gRVRreBcZIU aLmo3twAV3M4kgOIu5Xl0VCY3RXopQz/3aTxkgEU9QNqsi5JdReG+TSCHU6EaY/cDP J7u3z/esVU2eY+H4T9VXmkBct8Zu2UEbWvr57e3c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733181AbgKEXtF (ORCPT ); Thu, 5 Nov 2020 18:49:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:45930 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726801AbgKEXrX (ORCPT ); Thu, 5 Nov 2020 18:47:23 -0500 Received: from paulmck-ThinkPad-P72.home (50-39-104-11.bvtn.or.frontiernet.net [50.39.104.11]) (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 C383320A8B; Thu, 5 Nov 2020 23:47:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604620043; bh=oUwhdbK9KSe3gQBR4CXLgvIUkHvmer6tKhM7vfbOvtw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D3TlvljVeMGS6Rgdh1YntakbpDGFjMdmkcDyRzreqkAidPqSaOWI068F4Tvd9P2gD bLCJhfE48jUYj4u+P84RGk/7aP0+uV0980fgQqc2UWT3+SbGMeXg5W3L5NWKa6ndaV grgmmailze6Wqncfwvx2ki7WoIdkQfq1jZ5BlFbw= From: paulmck@kernel.org To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, "Paul E. McKenney" , Davidlohr Bueso Subject: [PATCH tip/core/rcu 03/28] locktorture: Track time of last ->writeunlock() Date: Thu, 5 Nov 2020 15:46:54 -0800 Message-Id: <20201105234719.23307-3-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20201105234658.GA23142@paulmck-ThinkPad-P72> References: <20201105234658.GA23142@paulmck-ThinkPad-P72> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" This commit adds a last_lock_release variable that tracks the time of the last ->writeunlock() call, which allows easier diagnosing of lock hangs when using a kernel debugger. Cc: Davidlohr Bueso Signed-off-by: Paul E. McKenney --- kernel/locking/locktorture.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index 62d215b..316531d 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -60,6 +60,7 @@ static struct task_struct **reader_tasks; static bool lock_is_write_held; static bool lock_is_read_held; +static unsigned long last_lock_release; struct lock_stress_stats { long n_lock_fail; @@ -632,6 +633,7 @@ static int lock_torture_writer(void *arg) lwsp->n_lock_acquired++; cxt.cur_ops->write_delay(&rand); lock_is_write_held = false; + WRITE_ONCE(last_lock_release, jiffies); cxt.cur_ops->writeunlock(); stutter_wait("lock_torture_writer"); -- 2.9.5