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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 51680C433F5 for ; Fri, 7 Sep 2018 20:59:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E78B520880 for ; Fri, 7 Sep 2018 20:59:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E78B520880 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727608AbeIHBmN (ORCPT ); Fri, 7 Sep 2018 21:42:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:39198 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726667AbeIHBmN (ORCPT ); Fri, 7 Sep 2018 21:42:13 -0400 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (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 EEC5220844; Fri, 7 Sep 2018 20:59:30 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.91) (envelope-from ) id 1fyNqk-0001hn-0E; Fri, 07 Sep 2018 16:59:30 -0400 Message-Id: <20180907205929.901024799@goodmis.org> User-Agent: quilt/0.65 Date: Fri, 07 Sep 2018 16:58:58 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-rt-users Cc: Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Paul Gortmaker , Julia Cartwright , Daniel Wagner , tom.zanussi@linux.intel.com, stable-rt@vger.kernel.org, Mike Galbraith Subject: [PATCH RT 01/24] sched/fair: Fix CFS bandwidth control lockdep DEADLOCK report References: <20180907205857.262840394@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14.63-rt41-rc2 stable review patch. If anyone has any objections, please let me know. ------------------ From: Mike Galbraith [ Upstream commit df7e8acc0c9a84979a448d215b8ef889efe4ac5a ] CFS bandwidth control yields the inversion gripe below, moving handling quells it. |======================================================== |WARNING: possible irq lock inversion dependency detected |4.16.7-rt1-rt #2 Tainted: G E |-------------------------------------------------------- |sirq-hrtimer/0/15 just changed the state of lock: | (&cfs_b->lock){+...}, at: [<000000009adb5cf7>] sched_cfs_period_timer+0x28/0x140 |but this lock was taken by another, HARDIRQ-safe lock in the past: (&rq->lock){-...} |and interrupts could create inverse lock ordering between them. |other info that might help us debug this: | Possible interrupt unsafe locking scenario: | CPU0 CPU1 | ---- ---- | lock(&cfs_b->lock); | local_irq_disable(); | lock(&rq->lock); | lock(&cfs_b->lock); | | lock(&rq->lock); Cc: stable-rt@vger.kernel.org Acked-by: Steven Rostedt (VMware) Signed-off-by: Mike Galbraith Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt (VMware) --- kernel/sched/fair.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 36ef77839be4..51ecea4f5d16 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4684,9 +4684,9 @@ void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) cfs_b->period = ns_to_ktime(default_cfs_period()); INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq); - hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); + hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD); cfs_b->period_timer.function = sched_cfs_period_timer; - hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); cfs_b->slack_timer.function = sched_cfs_slack_timer; } -- 2.18.0