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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 ED7BAC3F68F for ; Sat, 15 Feb 2020 00:37:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6C81206CC for ; Sat, 15 Feb 2020 00:37:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581727066; bh=YIkqP6FqAwpSoZTAWqZjr5NvJrMRZ5os7JHCxlxeJN0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=R0pcrmQs4YE+CS+1TsRxvXfp6pXcCezY8XrPs66fbyErQCXzeT43eu7Wffm4tRvmI eI5pNZYGX+a0oaT0oRg0M5dG4xcKTV+gzbWUCaihfSwTWWfHs5HN5gHLuuCt+kDKg+ Zq3adUHFqgWN2g4WeaQXU1XZdXtMdWBuOb/xE1Wg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727944AbgBOAh3 (ORCPT ); Fri, 14 Feb 2020 19:37:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:47548 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727943AbgBOAh3 (ORCPT ); Fri, 14 Feb 2020 19:37:29 -0500 Received: from paulmck-ThinkPad-P72.c.hoisthospitality.com (unknown [62.84.152.189]) (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 807422083B; Sat, 15 Feb 2020 00:37:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581727048; bh=YIkqP6FqAwpSoZTAWqZjr5NvJrMRZ5os7JHCxlxeJN0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BDzvGViPj1Vp+CWWn/hygokQ0sJhyO68ENOn+/Ry5RjywnMqAKQcYGVOZ0OFSVDnB n05ATXWQAUnz4gCXUOI74L/a4PzA86X27VPVRrBXWD0J+gI88Uh3kA759XK+mjJq2u nVC9IdI0MXsON4W6ix4UHwT3nnpmnqc5UO9/N/BA= 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, dipankar@in.ibm.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" Subject: [PATCH tip/core/rcu 04/18] torture: Forgive -EBUSY from boottime CPU-hotplug operations Date: Fri, 14 Feb 2020 16:36:57 -0800 Message-Id: <20200215003711.16463-4-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20200215003634.GA16227@paulmck-ThinkPad-P72> References: <20200215003634.GA16227@paulmck-ThinkPad-P72> Sender: rcu-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: "Paul E. McKenney" During boot, CPU hotplug is often disabled, for example by PCI probing. On large systems that take substantial time to boot, this can result in spurious RCU_HOTPLUG errors. This commit therefore forgives any boottime -EBUSY CPU-hotplug failures by adjusting counters to pretend that the corresponding attempt never happened. A non-splat record of the failed attempt is emitted to the console with the added string "(-EBUSY forgiven during boot)". Signed-off-by: Paul E. McKenney --- kernel/torture.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/kernel/torture.c b/kernel/torture.c index 7c13f55..e377b5b 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -84,6 +84,7 @@ bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, { unsigned long delta; int ret; + char *s; unsigned long starttime; if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) @@ -99,10 +100,16 @@ bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, (*n_offl_attempts)++; ret = cpu_down(cpu); if (ret) { + s = ""; + if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) { + // PCI probe frequently disables hotplug during boot. + (*n_offl_attempts)--; + s = " (-EBUSY forgiven during boot)"; + } if (verbose) pr_alert("%s" TORTURE_FLAG - "torture_onoff task: offline %d failed: errno %d\n", - torture_type, cpu, ret); + "torture_onoff task: offline %d failed%s: errno %d\n", + torture_type, cpu, s, ret); } else { if (verbose > 1) pr_alert("%s" TORTURE_FLAG @@ -137,6 +144,7 @@ bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes, { unsigned long delta; int ret; + char *s; unsigned long starttime; if (cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) @@ -150,10 +158,16 @@ bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes, (*n_onl_attempts)++; ret = cpu_up(cpu); if (ret) { + s = ""; + if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) { + // PCI probe frequently disables hotplug during boot. + (*n_onl_attempts)--; + s = " (-EBUSY forgiven during boot)"; + } if (verbose) pr_alert("%s" TORTURE_FLAG - "torture_onoff task: online %d failed: errno %d\n", - torture_type, cpu, ret); + "torture_onoff task: online %d failed%s: errno %d\n", + torture_type, cpu, s, ret); } else { if (verbose > 1) pr_alert("%s" TORTURE_FLAG -- 2.9.5