From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753405AbcH3NKd (ORCPT ); Tue, 30 Aug 2016 09:10:33 -0400 Received: from mailout2.samsung.com ([203.254.224.25]:40293 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753173AbcH3NK3 (ORCPT ); Tue, 30 Aug 2016 09:10:29 -0400 X-AuditID: cbfee68d-f79286d000007a9a-91-57c585c2f603 From: Jeehong Kim To: mingo@redhat.com Cc: peterz@infradead.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, ezjjilong@gmail.com, Jeehong Kim Subject: [PATCH V2] sched/fair: Fix that tasks are not constrained by cfs_b->quota on hotplug core, when hotplug core is offline and then online. Date: Tue, 30 Aug 2016 22:09:51 +0900 Message-id: <1472562591-20732-1-git-send-email-jhez.kim@samsung.com> X-Mailer: git-send-email 1.9.1 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrDLMWRmVeSWpSXmKPExsVy+t8zTd1DrUfDDf6vUbE49G83o0X3mz52 i5OzzzNaXD06idli6y1pi8u75rBZXDqwgMnieO8BJotbDxpZHDg9ds66y+6xeYWWx/t9V9k8 +rasYvT4vEkugDWKyyYlNSezLLVI3y6BK2PdlOlMBZOFK24tbmVqYFwl0MXIySEhYCLxeu4a JghbTOLCvfVsXYxcHEICKxklDv45wQhT1PjsMjtEYhajxN1jq5hBEkIC34GcryogNpuAhsTd 5nssILaIgIjEwYfbwSYxC0xhlPiyYj9YQlhgMqPE231ZIDaLgKrEzetNYKt5BVwkTmz7wAKx TU7i5LHJrCDNEgL97BL7e4+yQDQISHybfAjI5gBKyEpsOsAMUS8pcXDFDZYJjIILGBlWMYqm FiQXFCelFxnqFSfmFpfmpesl5+duYoQEcu8OxtsHrA8xCnAwKvHwTnA5Ei7EmlhWXJl7iNEU aMNEZinR5HxgvOSVxBsamxlZmJqYGhuZW5opifMqSv0MFhJITyxJzU5NLUgtii8qzUktPsTI xMEp1cB499qTJw8+X2E8strM7sZqxQ+cv1+wHDTrN/qkcjykc/Mlny886oq7L3TErfkr9qbu x8Tu6NvvMkIuaMiwLz7tLnLBsfveVtuXyl1L7quV2V36/OGFuv7k9OR8mRYhN+njwV5l099e ub7ja0qae41XyrnNDS9XnTziN2P+jv0Hj/JJHjjHMiX/vhJLcUaioRZzUXEiAHCtDvhfAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprJIsWRmVeSWpSXmKPExsVy+t9jQd1DrUfDDT4dkrc49G83o0X3mz52 i5OzzzNaXD06idli6y1pi8u75rBZXDqwgMnieO8BJotbDxpZHDg9ds66y+6xeYWWx/t9V9k8 +rasYvT4vEkugDWqgdEmIzUxJbVIITUvOT8lMy/dVsk7ON453tTMwFDX0NLCXEkhLzE31VbJ xSdA1y0zB+geJYWyxJxSoFBAYnGxkr4dpgmhIW66FjCNEbq+IUFwPUYGaCBhHWPGuinTmQom C1fcWtzK1MC4SqCLkZNDQsBEovHZZXYIW0ziwr31bF2MXBxCArMYJe4eW8UMkhAS+A7kfFUB sdkENCTuNt9jAbFFBEQkDj7cDtbALDCFUeLLiv1gCWGByYwSb/dlgdgsAqoSN683MYHYvAIu Eie2fWCB2CYncfLYZNYJjNwLGBlWMUqkFiQXFCel5xrmpZbrFSfmFpfmpesl5+duYgRHyzOp HYwHd7kfYhTgYFTi4T3AcjRciDWxrLgy9xCjBAezkgjv0RagEG9KYmVValF+fFFpTmrxIUZT oAMmMkuJJucDIzmvJN7Q2MTMyNLIzNjE3NhYSZz38f91YUIC6YklqdmpqQWpRTB9TBycUg2M jNmGQea+Bhw9bKeZzvySrehruTDTn2P/912T5gf/LJb517KtdSufZmBi+oeljI5S3cffFK2u 6u78bDDD2eXVrolPtjJmNe/cdtTuePj8srnZd5qmyb/Xnfq5uOaQwpxfe9r0f/np+LWtT+Ko WMhk23dspmJTZJjnbv6YaMHpk5yL/25PVdBVYinOSDTUYi4qTgQASBv51KwCAAA= DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In case that CONFIG_HOTPLUG_CPU and CONFIG_CFS_BANDWIDTH is turned on and tasks in bandwidth controlled task group run on hotplug core, the tasks are not controlled by cfs_b->quota when hotplug core is offline and then online. The remaining tasks in task group consume all of cfs_b->quota on other cores. The cause of this problem is described as below: 1. When hotplug core is offline while tasks in task group run on hotplug core, unregister_fair_sched_group() deletes leaf_cfs_rq_list of tg->cfs_rq[cpu] from &rq_of(cfs_rq)->leaf_cfs_rq_list. 2. Then, when hotplug core is online, update_runtime_enabled() registers cfs_b->quota on cfs_rq->runtime_enabled of all leaf cfs_rq on runqueue. However, because this is before enqueue_entity() adds &cfs_rq->leaf_cfs_rq_list on &rq_of(cfs_rq)->leaf_cfs_rq_list, cfs->quota is not register on cfs_rq->runtime_enabled. To resolve this problem, this patch makes update_runtime_enabled() registers cfs_b->quota by using walk_tg_tree_from(). Signed-off-by: Jeehong Kim --- kernel/sched/fair.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6488815..63b376d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4373,17 +4373,27 @@ static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) hrtimer_cancel(&cfs_b->slack_timer); } -static void __maybe_unused update_runtime_enabled(struct rq *rq) +static int __maybe_unused __update_runtime_enabled(struct task_group *tg, void *data) { - struct cfs_rq *cfs_rq; + struct rq *rq = data; + struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)]; + struct cfs_bandwidth *cfs_b = &cfs_rq->tg->cfs_bandwidth; - for_each_leaf_cfs_rq(rq, cfs_rq) { - struct cfs_bandwidth *cfs_b = &cfs_rq->tg->cfs_bandwidth; + raw_spin_lock(&cfs_b->lock); + cfs_rq->runtime_enabled = cfs_b->quota != RUNTIME_INF; + raw_spin_unlock(&cfs_b->lock); - raw_spin_lock(&cfs_b->lock); - cfs_rq->runtime_enabled = cfs_b->quota != RUNTIME_INF; - raw_spin_unlock(&cfs_b->lock); - } + return 0; +} + +static void __maybe_unused update_runtime_enabled(struct rq *rq) +{ + struct cfs_rq *cfs_rq = &rq->cfs; + + /* register cfs_b->quota on the whole tg tree */ + rcu_read_lock(); + walk_tg_tree_from(cfs_rq->tg, __update_runtime_enabled, tg_nop, (void *)rq); + rcu_read_unlock(); } --