From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753777Ab2LLJje (ORCPT ); Wed, 12 Dec 2012 04:39:34 -0500 Received: from moutng.kundenserver.de ([212.227.126.187]:54026 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752871Ab2LLJja convert rfc822-to-8bit (ORCPT ); Wed, 12 Dec 2012 04:39:30 -0500 Message-ID: <1355305167.6142.15.camel@marge.simpson.net> Subject: RE: [PATCH] sched/rt: don't enable runtime if already enabled From: Mike Galbraith To: Neil Zhang Cc: "peterz@infradead.org" , "mingo@kernel.org" , Chao Xie , "linux-kernel@vger.kernel.org" Date: Wed, 12 Dec 2012 10:39:27 +0100 In-Reply-To: <175CCF5F49938B4D99B2E3EF7F558EBE1C737A51CB@SC-VEXCH4.marvell.com> References: <1354521675-31245-1-git-send-email-zhangwm@marvell.com> <175CCF5F49938B4D99B2E3EF7F558EBE1C7364A68B@SC-VEXCH4.marvell.com> <175CCF5F49938B4D99B2E3EF7F558EBE1C737A51CB@SC-VEXCH4.marvell.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 Content-Transfer-Encoding: 8BIT Mime-Version: 1.0 X-Provags-ID: V02:K0:DzYutkpm8a+yUbJyyclRnaxhNEqbft1QpOIIb04MIJz 8aTxzOTAhhdgqZ9qRpH2/Cudo59sYo+Nkvf3pm9IBU6xeYkg7b xRJ07dfn9iri+FTjw4qrc1ZaQplVhKWxozksbmxxvaprLDvse4 WDR7VMm0o2ywh+DjBIDnff7e+TuJnT9fcYXAlXP44K5x925mzt HIP87+BSrMa4qkDjLn8LDm+0Ej82NLkyF99ROosy+rXsgjRC7Q 75frfYE7Ikfuyv5JjPFIFXgan1lX7sOABi3MGKP0BQs02q0FoO v/vNQ+z3YWEKtIyUNm8EYdaIkAIQSajsrYs1CTyWogOtHPyYul viy4XvEBWZsNwBd2yRZ4E9lRNRfokQn1Z1y40CZmLZKZm5Vp1y lKqpJZL4o99Eg== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2012-12-11 at 21:38 -0800, Neil Zhang wrote: > Ingo and All, Hm, /me wonders why we would even need update_runtime() handler. We disable at CPU_DOWN_PREPARE in update_runtime(), again at CPU_DYING in migration_call(), and enable at CPU_ONLINE in both. > -----Original Message----- > From: Neil Zhang > Sent: 2012年12月4日 17:31 > To: Neil Zhang; peterz@infradead.org; mingo@kernel.org > Cc: Chao Xie; linux-kernel@vger.kernel.org > Subject: RE: [PATCH] sched/rt: don't enable runtime if already enabled > > Hi All, > > -----Original Message----- > From: Neil Zhang [mailto:zhangwm@marvell.com] > Sent: 2012年12月3日 16:01 > To: mingo@redhat.com; peterz@infradead.org > Cc: Chao Xie; linux-kernel@vger.kernel.org; Neil Zhang > Subject: [PATCH] sched/rt: don't enable runtime if already enabled > > There are two paths will call __enable_runtime, they are enable_runtime and rq_online. Don't enable runtime again if it is already enabled. > It can fix the following kernel BUG when do cpu hotplug while there are realtime threads running. > > [ 3347.091644] kernel BUG at kernel/sched/rt.c:687! > [ 3347.091674] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM [ 3347.091674] Modules linked in: cidatattydev(O) gs_diag(O) diag(O) gs_modem(O) ccinetdev(O) cci_datastub(O) citty(O) msocke > [ 3347.091705] CPU: 1 Tainted: G O (3.4.5+ #439) > [ 3347.091735] PC is at __disable_runtime+0x1e4/0x240 [ 3347.091735] LR is at __disable_runtime+0x1dc/0x240 > [ 3347.091735] pc : [] lr : [] psr: > a0000093 > [ 3347.091735] sp : e0061dc8 ip : c0807861 fp : c07a9740 [ 3347.091766] r10: c1a0b740 r9 : ffffffff r8 : fd050f80 [ 3347.091766] r7 : 00000002 r6 : 000003f8 r5 : c1a13740 r4 : c1a137d8 [ 3347.091766] r3 : ffffffff r2 : e0061dbc r1 : c06b11b6 r0 : 00000037 [ 3347.091796] Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel [ 3347.091796] Control: 10c53c7d Table: 21e5004a DAC: 00000015 > > Signed-off-by: Neil Zhang > --- > kernel/sched/rt.c | 8 +++++--- > 1 files changed, 5 insertions(+), 3 deletions(-) > > diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 418feb0..6525e5b 100644 > --- a/kernel/sched/rt.c > +++ b/kernel/sched/rt.c > @@ -722,9 +722,11 @@ static void __enable_runtime(struct rq *rq) > > raw_spin_lock(&rt_b->rt_runtime_lock); > raw_spin_lock(&rt_rq->rt_runtime_lock); > - rt_rq->rt_runtime = rt_b->rt_runtime; > - rt_rq->rt_time = 0; > - rt_rq->rt_throttled = 0; > + if (rt_rq->rt_runtime == RUNTIME_INF) { > + rt_rq->rt_runtime = rt_b->rt_runtime; > + rt_rq->rt_time = 0; > + rt_rq->rt_throttled = 0; > + } > raw_spin_unlock(&rt_rq->rt_runtime_lock); > raw_spin_unlock(&rt_b->rt_runtime_lock); > } > -- > 1.7.4.1 > > Ingo seems use another mail now, update the To list. > > Best Regards, > Neil Zhang > > Please help review it. > > Best Regards, > Neil Zhang > NР骒rybX肚v^)藓{.n+伐{赙zXФ≤}财z&j:+v赙zZ++zf＂h~izwア?ㄨ&)撷f^j谦ym@Aa囤0鹅hi