Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751957AbaAOLai (ORCPT ); Wed, 15 Jan 2014 06:30:38 -0500 Received: from merlin.infradead.org ([205.233.59.134]:34469 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751473AbaAOLag (ORCPT ); Wed, 15 Jan 2014 06:30:36 -0500 Date: Wed, 15 Jan 2014 12:30:15 +0100 From: Peter Zijlstra To: Michael wang Cc: Daniel Lezcano , raistlin@linux.it, juri.lelli@gmail.com, Ingo Molnar , Linux Kernel Mailing List Subject: Re: [BUG] [ tip/sched/core ] System unresponsive after booting Message-ID: <20140115113015.GB31570@twins.programming.kicks-ass.net> References: <52D64676.4040000@linaro.org> <52D65423.2070706@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <52D65423.2070706@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 15, 2014 at 05:25:55PM +0800, Michael wang wrote: > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 0326c06..bf4a6ed 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -3464,6 +3464,10 @@ int sched_setscheduler(struct task_struct *p, int > policy, > .sched_policy = policy, > .sched_priority = param->sched_priority > }; > + > + if (fair_policy(policy)) > + attr.sched_nice = PRIO_TO_NICE(attr.sched_priority); > + > return __sched_setscheduler(p, &attr, true); > } > EXPORT_SYMBOL_GPL(sched_setscheduler); > @@ -3494,6 +3498,10 @@ int sched_setscheduler_nocheck(struct task_struct > *p, int policy, > .sched_policy = policy, > .sched_priority = param->sched_priority > }; > + > + if (fair_policy(policy)) > + attr.sched_nice = PRIO_TO_NICE(attr.sched_priority); > + > return __sched_setscheduler(p, &attr, false); > } That seems wrong; the manpage confirms, from sched_setscheduler(2): For processes scheduled under one of the normal scheduling policies (SCHED_OTHER, SCHED_IDLE, SCHED_BATCH), sched_priority is not used in scheduling decisions (it must be speci‐ fied as 0). That said; we should probably preserve the nice value, which with the current code we reset to 0. --- kernel/sched/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0326c06953eb..f3abbb7dae62 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3462,7 +3462,8 @@ int sched_setscheduler(struct task_struct *p, int policy, { struct sched_attr attr = { .sched_policy = policy, - .sched_priority = param->sched_priority + .sched_priority = param->sched_priority, + .sched_nice = PRIO_TO_NICE(p->static_prio), }; return __sched_setscheduler(p, &attr, true); } @@ -3492,7 +3493,8 @@ int sched_setscheduler_nocheck(struct task_struct *p, int policy, { struct sched_attr attr = { .sched_policy = policy, - .sched_priority = param->sched_priority + .sched_priority = param->sched_priority, + .sched_nice = PRIO_TO_NICE(p->static_prio), }; return __sched_setscheduler(p, &attr, false); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/