From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932727AbbCQLdp (ORCPT ); Tue, 17 Mar 2015 07:33:45 -0400 Received: from mga02.intel.com ([134.134.136.20]:13720 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932213AbbCQLdk (ORCPT ); Tue, 17 Mar 2015 07:33:40 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,416,1422950400"; d="scan'208";a="468350709" From: Wanpeng Li To: Ingo Molnar , Peter Zijlstra Cc: Juri Lelli , linux-kernel@vger.kernel.org, Wanpeng Li Subject: [PATCH v3 2/2] sched/deadline: fix rt runtime corrupt when dl refuse a smaller bandwidth Date: Tue, 17 Mar 2015 19:15:31 +0800 Message-Id: <1426590931-4639-2-git-send-email-wanpeng.li@linux.intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1426590931-4639-1-git-send-email-wanpeng.li@linux.intel.com> References: <1426590931-4639-1-git-send-email-wanpeng.li@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dl class will refuse the bandwidth to be set to some value smaller than the current 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 corrupted 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. Acked-by: Juri Lelli Signed-off-by: Wanpeng Li --- v2 -> v3: * update changelog 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; -- 1.9.1