From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2FD1BCA9EC5 for ; Wed, 30 Oct 2019 09:32:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0983B21835 for ; Wed, 30 Oct 2019 09:32:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726321AbfJ3Jcs convert rfc822-to-8bit (ORCPT ); Wed, 30 Oct 2019 05:32:48 -0400 Received: from mx21.baidu.com ([220.181.3.85]:52083 "EHLO baidu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726028AbfJ3Jcr (ORCPT ); Wed, 30 Oct 2019 05:32:47 -0400 Received: from BJHW-Mail-Ex14.internal.baidu.com (unknown [10.127.64.37]) by Forcepoint Email with ESMTPS id 38CB867CA021E; Wed, 30 Oct 2019 17:32:40 +0800 (CST) Received: from BJHW-Mail-Ex13.internal.baidu.com (10.127.64.36) by BJHW-Mail-Ex14.internal.baidu.com (10.127.64.37) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Wed, 30 Oct 2019 17:32:41 +0800 Received: from BJHW-Mail-Ex13.internal.baidu.com ([100.100.100.36]) by BJHW-Mail-Ex13.internal.baidu.com ([100.100.100.36]) with mapi id 15.01.1713.004; Wed, 30 Oct 2019 17:32:41 +0800 From: "Li,Rongqing" To: "linux-kernel@vger.kernel.org" CC: "tj@kernel.org" , "lizefan@huawei.com" , "hannes@cmpxchg.org" , "cgroups@vger.kernel.org" Subject: mount cgroup with "already mounted or cgroup busy" Thread-Topic: mount cgroup with "already mounted or cgroup busy" Thread-Index: AdWPA9906A1LJjv0Rpi5m0VcmmdBIA== Date: Wed, 30 Oct 2019 09:32:41 +0000 Message-ID: <11be9352e1e54ebebad078b1dac7b670@baidu.com> Accept-Language: zh-CN, en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.22.198.13] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi: I meet a issue, and not sure if it is normal Using the below script, the last line mount will fail after unmount And it will fail until reboot system mount -t cgroup -o cpu,cpuset xx cgroup mkdir cgroup/x rmdir cgroup/x umount cgroup mount -t cgroup -o cpu xx cgroup mount: xx already mounted or cgroup busy but if I add sleep, it will success mount -t cgroup -o cpu,cpuset xx cgroup mkdir cgroup/x rmdir cgroup/x sleep 10 <<<<========== umount cgroup mount -t cgroup -o cpu xx cgroup - Li RongQing