Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753335AbbBZJzV (ORCPT ); Thu, 26 Feb 2015 04:55:21 -0500 Received: from service87.mimecast.com ([91.220.42.44]:49351 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752696AbbBZJzM convert rfc822-to-8bit (ORCPT ); Thu, 26 Feb 2015 04:55:12 -0500 Message-ID: <54EEED7C.2030504@arm.com> Date: Thu, 26 Feb 2015 09:55:08 +0000 From: Juri Lelli User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Wanpeng Li , Ingo Molnar , Peter Zijlstra CC: "juri.lelli@gmail.com" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH RESEND v2] sched/deadline: fix rt runtime corrupt when dl refuse a smaller bandwidth References: <1424839042-97347-1-git-send-email-wanpeng.li@linux.intel.com> In-Reply-To: <1424839042-97347-1-git-send-email-wanpeng.li@linux.intel.com> X-OriginalArrivalTime: 26 Feb 2015 09:55:08.0604 (UTC) FILETIME=[4DD80FC0:01D051AA] X-MC-Unique: 115022609550907401 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2057 Lines: 63 Hi, On 25/02/2015 04:37, Wanpeng Li wrote: > Dl class will refuse the bandwidth being set to some value smaller > than the currently allocated bandwidth in any of the root_domains > through sched_rt_runtime_us and sched_rt_period_us. RT runtime will > be set according to sched_rt_runtime_us before dl class verify if > the new bandwidth is suitable in the case of !CONFIG_RT_GROUP_SCHED. > > However, rt runtime will be corrupt if dl refuse the new bandwidth > since there is no undo to reset the rt runtime to the old value. > > This patch fix it by verifying new bandwidth for deadline in advance. > Looks good, thanks! Acked-by: Juri Lelli > Cc: Juri Lelli > Signed-off-by: Wanpeng Li > --- > v1 -> v2: > * move sched_dl_global_constraints before sched_rt_global_constraints, > and change the name of the former to sched_dl_global_validate(). > > kernel/sched/core.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 97fe79c..e884909 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -7815,7 +7815,7 @@ static int sched_rt_global_constraints(void) > } > #endif /* CONFIG_RT_GROUP_SCHED */ > > -static int sched_dl_global_constraints(void) > +static int sched_dl_global_validate(void) > { > u64 runtime = global_rt_runtime(); > u64 period = global_rt_period(); > @@ -7916,11 +7916,11 @@ int sched_rt_handler(struct ctl_table *table, int write, > if (ret) > goto undo; > > - ret = sched_rt_global_constraints(); > + ret = sched_dl_global_validate(); > if (ret) > goto undo; > > - ret = sched_dl_global_constraints(); > + ret = sched_rt_global_constraints(); > if (ret) > goto undo; > > -- 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/