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Lunev" Message-ID: <43df6148-cec5-a866-4b81-7f4020c70f7d@openvz.org> Date: Fri, 31 Jul 2020 13:31:51 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 In-Reply-To: <20200731102531.GC177875@stefanha-x1.localdomain> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Content-Language: en-US X-ClientProxiedBy: HE1PR1001CA0012.EURPRD10.PROD.OUTLOOK.COM (2603:10a6:3:f7::22) To AM6PR08MB4214.eurprd08.prod.outlook.com (2603:10a6:20b:8d::30) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [192.168.1.27] (31.148.204.195) by HE1PR1001CA0012.EURPRD10.PROD.OUTLOOK.COM (2603:10a6:3:f7::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3239.18 via Frontend Transport; Fri, 31 Jul 2020 10:31:53 +0000 X-Originating-IP: [31.148.204.195] X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: d6cf4617-db05-41ec-cc01-08d8353cf169 X-MS-TrafficTypeDiagnostic: AM6PR08MB3224: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:10000; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: Ig7WUdpVBtYYSSIPqgkbyDfb46b6z6pnFJepTZXI3E3Vdif+5HmGaqUza2VsnPETtpYu0DE5s8NT5kqn4ZUwvYihXF3/lo2C+MWhCftJQfQssZCzbPG92Sc/aJmg+nB4k9hCI411VF538ClnmYlg5ffjVVHrYENw+OqQOIoFDEGJ7/WNGidWCwYtK8IwofEl+du67esPEIyO+T0gaIcmao8Z0Iednh8ichDBRH7iS8bWD8VDD1DQfX8LYAzGCmXPSucjnIt/taE4AO4yeTqTy089taMAOQbwpQqAFQkCwGLRj5/4PchTaEXDfSEI+Fl85VXX62X+MiwL5jAzG26cHftwNUPVYk00TRLJLLqFFZrN1QloEFUPOIj6cnC8mhLQ X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:AM6PR08MB4214.eurprd08.prod.outlook.com; PTR:; CAT:NONE; SFTY:; SFS:(4636009)(136003)(376002)(366004)(346002)(396003)(39840400004)(6486002)(36756003)(53546011)(83170400001)(5660300002)(956004)(16526019)(2616005)(478600001)(186003)(52116002)(83380400001)(2906002)(6916009)(42882007)(26005)(31696002)(66946007)(66476007)(66556008)(16576012)(54906003)(316002)(8936002)(31686004)(8676002)(4326008)(43740500002); DIR:OUT; SFP:1102; X-MS-Exchange-AntiSpam-MessageData: ehm7dPLayH4nzuYtbI7wArQqrxgUOTuBlqQ8Gh1KJU4B68lDYn4DaoP82fRrApYsKsIt7d7Z4BrDeekzEv0p0tyUIDkjlkUUL6nWKgbWJL4JV5hbgFtoQ5EE4F1+cF6TmG0WDMB74Yqhos0/jlMe/scGWk4qBhY4wFNwubR/RavD7p1xgmge0CQAkSQLjpDZxjihAenN/3GvxIvt6bgMC6YAtHSeGzBZNOHDob6oN9XVu7c6ADJYDfXfJ52yolDVa4ebCEyhtZ7ywnqUEt7ZbJokLn7QmcCp+JoD+Ddeo8dcVJqHsVhqRxf+esJWKXvR7P2mUSwdqruqc2nXb7zZQGJ9HrSq19U350c5xuNwbnOiFoKvRdUgRz3ny8wmVDx6TYJiFHJ9k+DmywJNPsb/qFe6SA0LP1Nrn1KVdnr30rFtCmUA+gCMLYrNr3sZmgzX32oO/OSv4RFSGw5NsMdL10z8vgEeb2ldkHXv5TkiZoh11XOSRR72YATZww/rE0xRUE0hcHdfXOVrq3NX80Qaluoz4ngF74arkoqa8tO/ajgvMysu1/g9fzNY60Ku3XsDX0ZUWAcgfsqJKdaanMGBJxd0k4JNLPh+6nQUz3/1ZZ0cgjjrWAuC/J6aB5JiF89F7Vz3zgOxAUVxnjELK7k4/w== X-OriginatorOrg: openvz.org X-MS-Exchange-CrossTenant-Network-Message-Id: d6cf4617-db05-41ec-cc01-08d8353cf169 X-MS-Exchange-CrossTenant-AuthSource: AM6PR08MB4214.eurprd08.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 31 Jul 2020 10:31:53.8407 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 0bc7f26d-0264-416e-a6fc-8352af79c58f X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: ysNDp64FTMAobYUnD8zEtR/dqo8sjNS3n1XzdSIcD0wwEmI51T1Ge1GK5otZBO3+YchdP7qLt6SN0rV3yGGuFw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM6PR08MB3224 Received-SPF: pass client-ip=40.107.7.91; envelope-from=den@virtuozzo.com; helo=EUR04-HE1-obe.outbound.protection.outlook.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/31 06:31:54 X-ACL-Warn: Detected OS = Windows NT kernel [generic] [fuzzy] X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, DKIM_INVALID=0.1, DKIM_SIGNED=0.1, HEADER_FROM_DIFFERENT_DOMAINS=1, MSGID_FROM_MTA_HEADER=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 7/31/20 1:25 PM, Stefan Hajnoczi wrote: > On Fri, Jul 10, 2020 at 08:27:09PM +0300, Denis V. Lunev wrote: >> There are severe delays with IO requests processing if QEMU is running in >> virtual machine or over software defined storage. Such delays potentially >> results in unpredictable guest behavior. For example, guests over IDE or >> SATA drive could remount filesystem read-only if write is performed >> longer than 10 seconds. >> >> Such reports are very complex to process. Some good starting point for this >> seems quite reasonable. This patch provides one. It adds logging of such >> potentially dangerous long IO operations. >> >> Signed-off-by: Denis V. Lunev >> CC: Vladimir Sementsov-Ogievskiy >> CC: Kevin Wolf >> CC: Max Reitz > If I understand correctly this only reports completed I/Os, so if the > host hasn't given up on an I/O request yet then QEMU will not report it > is taking a long time. In the meantime the guest could start printing > timeout errors. > > I think this patch series is good as it is. In the future maybe a QMP > command that lists in-flight I/O requests would be nice. That helps > when troubleshooting I/Os that are hung. We could dump requests at block level, we do have proper lists, but the would be a little bit different. Anyway, I __DO__ like this idea, I have missed this somehow :) Thank you for the suggestion,     Den