From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753500Ab1HNP7C (ORCPT ); Sun, 14 Aug 2011 11:59:02 -0400 Received: from hera.kernel.org ([140.211.167.34]:51208 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751517Ab1HNP67 (ORCPT ); Sun, 14 Aug 2011 11:58:59 -0400 Date: Sun, 14 Aug 2011 15:58:42 GMT From: tip-bot for Mike Galbraith Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, efault@gmx.de, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, efault@gmx.de, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <1311779695.8691.2.camel@marge.simson.net> References: <1311779695.8691.2.camel@marge.simson.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched: fix broken SCHED_RESET_ON_FORK handling Git-Commit-ID: c350a04efd1c89cd256b2abc8f07a21d0d53ff24 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Sun, 14 Aug 2011 15:58:44 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c350a04efd1c89cd256b2abc8f07a21d0d53ff24 Gitweb: http://git.kernel.org/tip/c350a04efd1c89cd256b2abc8f07a21d0d53ff24 Author: Mike Galbraith AuthorDate: Wed, 27 Jul 2011 17:14:55 +0200 Committer: Ingo Molnar CommitDate: Sun, 14 Aug 2011 12:00:43 +0200 sched: fix broken SCHED_RESET_ON_FORK handling Setting child->prio = current->normal_prio _after_ SCHED_RESET_ON_FORK has been handled for an RT parent gives birth to a deranged mutant child with non-RT policy, but RT prio and sched_class. Move PI leakage protection up, always set priorities and weight, and if the child is leaving RT class, reset rt_priority to the proper value. Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1311779695.8691.2.camel@marge.simson.net Signed-off-by: Ingo Molnar --- kernel/sched.c | 25 ++++++++++++------------- 1 files changed, 12 insertions(+), 13 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index b1e8f0e..cf427bb 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2844,19 +2844,23 @@ void sched_fork(struct task_struct *p) p->state = TASK_RUNNING; /* + * Make sure we do not leak PI boosting priority to the child. + */ + p->prio = current->normal_prio; + + /* * Revert to default priority/policy on fork if requested. */ if (unlikely(p->sched_reset_on_fork)) { - if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) { + if (task_has_rt_policy(p)) { p->policy = SCHED_NORMAL; - p->normal_prio = p->static_prio; - } - - if (PRIO_TO_NICE(p->static_prio) < 0) { p->static_prio = NICE_TO_PRIO(0); - p->normal_prio = p->static_prio; - set_load_weight(p); - } + p->rt_priority = 0; + } else if (PRIO_TO_NICE(p->static_prio) < 0) + p->static_prio = NICE_TO_PRIO(0); + + p->prio = p->normal_prio = __normal_prio(p); + set_load_weight(p); /* * We don't need the reset flag anymore after the fork. It has @@ -2865,11 +2869,6 @@ void sched_fork(struct task_struct *p) p->sched_reset_on_fork = 0; } - /* - * Make sure we do not leak PI boosting priority to the child. - */ - p->prio = current->normal_prio; - if (!rt_prio(p->prio)) p->sched_class = &fair_sched_class;