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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74CDDC433EF for ; Fri, 4 Feb 2022 23:53:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378483AbiBDXxo (ORCPT ); Fri, 4 Feb 2022 18:53:44 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:45758 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378359AbiBDXxc (ORCPT ); Fri, 4 Feb 2022 18:53:32 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 13AA2B83975; Fri, 4 Feb 2022 23:53:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B35BBC340F1; Fri, 4 Feb 2022 23:53:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1644018809; bh=gMEkExdEIHtGZYJMcRMC5CtUw2Kr5Mwkvh0M24YUqF4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KhV/RYYSsjDjI0qNGqJ2DYRoSz3pTf8cKxagRcd+9QoYKmI3uUV7Mam1AktBDSs6K 6y8L3f429/ykLR6JpaWRKCrcJEqzKXn8T9jmM6VKzwJ7QbbZDGU69Z0ErpSS6J489J bqvvHrLbHICjkSINdERcgRtIuHeE6DCFtvsEyn2b4xW3rU50bZp5dTAHw7JxZ1eeNx hYc2itObZwxmBahnDjoGJD9HoPbcZrU95Nm5omIRgNjdsMGAIDObXCcHlSmRD3vN/h toLSPJFe5M/VX/kf22JQRro5foc+1Y3DnQWzp7hGFEG7e0uv2DCiJ8rEvz46O2CfhS gnX/siPw5wkQQ== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 78C555C08B7; Fri, 4 Feb 2022 15:53:29 -0800 (PST) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, rostedt@goodmis.org, "Paul E. McKenney" Subject: [PATCH rcu 3/8] rcutorture: Increase visibility of forward-progress hangs Date: Fri, 4 Feb 2022 15:53:22 -0800 Message-Id: <20220204235327.2948-3-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20220204235321.GA2511@paulmck-ThinkPad-P17-Gen-1> References: <20220204235321.GA2511@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This commit adds a few pr_alert() calls to rcutorture's forward-progress testing in order to better diagnose shutdown-time hangs. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcutorture.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 00400aef58184..fefc3fa1a9c2a 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -2281,6 +2281,7 @@ static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp, unsigned long stopat; static DEFINE_TORTURE_RANDOM(trs); + pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); if (!cur_ops->sync) return; // Cannot do need_resched() forward progress testing without ->sync. if (cur_ops->call && cur_ops->cb_barrier) { @@ -2325,6 +2326,7 @@ static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp, if (selfpropcb) { WRITE_ONCE(fcs.stop, 1); cur_ops->sync(); /* Wait for running CB to complete. */ + pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id); cur_ops->cb_barrier(); /* Wait for queued callbacks. */ } @@ -2353,6 +2355,7 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp) unsigned long stopat; unsigned long stoppedat; + pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); if (READ_ONCE(rcu_fwd_emergency_stop)) return; /* Get out of the way quickly, no GP wait! */ if (!cur_ops->call) @@ -2414,6 +2417,7 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp) n_launders_cb_snap = READ_ONCE(rfp->n_launders_cb); cver = READ_ONCE(rcu_torture_current_version) - cver; gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); + pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id); cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */ (void)rcu_torture_fwd_prog_cbfree(rfp); -- 2.31.1.189.g2e36527f23