From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751709AbaKZAy5 (ORCPT ); Tue, 25 Nov 2014 19:54:57 -0500 Received: from mga11.intel.com ([192.55.52.93]:9498 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751061AbaKZAy4 (ORCPT ); Tue, 25 Nov 2014 19:54:56 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,459,1413270000"; d="scan'208";a="638122941" Date: Wed, 26 Nov 2014 08:34:32 +0800 From: Wanpeng Li To: Ingo Molnar , Peter Zijlstra Cc: Juri Lelli , Kirill Tkhai , linux-kernel@vger.kernel.org, Wanpeng Li Subject: Re: [PATCH v6 1/7] sched/deadline: fix start high-res preemption tick for a non-leftmost task Message-ID: <20141126003432.GA6852@kernel> Reply-To: Wanpeng Li References: <1416962647-76792-1-git-send-email-wanpeng.li@linux.intel.com> <1416962647-76792-3-git-send-email-wanpeng.li@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1416962647-76792-3-git-send-email-wanpeng.li@linux.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Replace the subject by "Subject: [PATCH v6 2/7] sched/deadline: fix rt runtime corrupt when dl refuse a smaller bandwidth" On Wed, Nov 26, 2014 at 08:44:02AM +0800, 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. > >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 603c462..981f075 100644 >--- a/kernel/sched/core.c >+++ b/kernel/sched/core.c >@@ -7808,7 +7808,7 @@ 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(); >@@ -7909,11 +7909,11 @@ 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; > >-- >1.9.1