From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Galbraith Subject: Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Date: Tue, 19 Jan 2016 05:41:56 +0100 Message-ID: <1453178516.4217.2.camel@gmail.com> References: <1453108103.4123.4.camel@gmail.com> <20160118201828.GE12309@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Thomas Gleixner , LKML , linux-rt-users To: Sebastian Andrzej Siewior Return-path: Received: from mail-wm0-f50.google.com ([74.125.82.50]:38159 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756186AbcASEmA (ORCPT ); Mon, 18 Jan 2016 23:42:00 -0500 In-Reply-To: <20160118201828.GE12309@linutronix.de> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Mon, 2016-01-18 at 21:18 +0100, Sebastian Andrzej Siewior wrote: > > --- a/kernel/sched/core.c > > +++ b/kernel/sched/core.c > > @@ -3542,6 +3542,15 @@ asmlinkage __visible void __sched notrac > > if (likely(!preemptible())) > > return; > >=20 > > +#ifdef CONFIG_PREEMPT_LAZY > > + /* > > + * Check for lazy preemption > > + */ > > + if (current_thread_info()->preempt_lazy_count && > > + !test_thread_flag(TIF_NEED_RESCHED)) > > + return; > > +#endif > > + >=20 > And this is a new piece. So you forbid that tasks leave the CPU if > lazy_count > 0. Let me look closed why this is happening and if this = is > v4.1 =E2=80=A6 v4.4 or not. That check wants a !rt_task(current) qualifier anyway. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html