From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933244AbdENShi (ORCPT ); Sun, 14 May 2017 14:37:38 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:58287 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933216AbdENShf (ORCPT ); Sun, 14 May 2017 14:37:35 -0400 Message-Id: <20170514183613.836520655@linutronix.de> User-Agent: quilt/0.63-1 Date: Sun, 14 May 2017 20:27:33 +0200 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Ingo Molnar , Steven Rostedt , Mark Rutland Subject: [patch 17/18] sched: Enable might_sleep() checks early References: <20170514182716.347236777@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=sched--Enable-might_sleep---checks-early.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org might_sleep() checks are enabled after the boot process is done. That hides bugs in the smp bringup and driver initialization code. Enable it right when the scheduler starts working, i.e. when init task and kthreadd have been created and right before the idle task enables preemption. Signed-off-by: Thomas Gleixner --- init/main.c | 2 ++ kernel/sched/core.c | 4 +++- 2 files changed, 5 insertions(+), 1 deletion(-) --- a/init/main.c +++ b/init/main.c @@ -410,6 +410,8 @@ static noinline void __ref rest_init(voi * at least once to get things moving: */ init_idle_bootup_task(current); + /* Enable might_sleep() checks */ + system_state = SYSTEM_BOOTING_UP; schedule_preempt_disabled(); /* Call into cpu_idle with preempt disabled */ cpu_startup_entry(CPUHP_ONLINE); --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6226,8 +6226,10 @@ void ___might_sleep(const char *file, in if ((preempt_count_equals(preempt_offset) && !irqs_disabled() && !is_idle_task(current)) || - system_state != SYSTEM_RUNNING || oops_in_progress) + system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING || + oops_in_progress) return; + if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) return; prev_jiffy = jiffies;