From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from NAM11-BN8-obe.outbound.protection.outlook.com (mail-bn8nam11on2125.outbound.protection.outlook.com [40.107.236.125]) by sourceware.org (Postfix) with ESMTPS id 2AB953858C3B for ; Mon, 30 Aug 2021 02:15:33 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 2AB953858C3B ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=A8kYtYRxBXDvd1eqfMCJbOyw3biFUSp0U49RZrWM2Kl3zRtaS3pb/YQuX6ghLRZZrB+dBt3fd9bzL2x4K7PPBqpjTaplE5dixzR/6oCcZP2z944dr8zny4Q4WvNYC/VP68IN9PLY6mofXTb3qE3zdl/4wmB/Ree8Y0ONfw2xL7GkHTpajc5oE8zhcIVrWyio1iPQ+LCle26QZvmb2syKdZcZJ6rYhkmxIprShne7MXCDePZf0vafkwznetanRjyTKkaeTvKZufz6OeZPAXI89o7pZv5NOwxDf6PHr6vem9hq2A+wE1xpX9dPY8+I9ffmDfM/zmPwH9FxzJLz8cXZ8g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=afM2MlsqQJm5Ayh3DLcSx/BggGrtDJ8VC6GoZT7fjwY=; b=QpAqu+RaNaSN1SR/ee4oI3KfEUonB1eWbZnc/Tp+wDGvrNzjQoxzz+lwXk8uohcurhJG2QFOTBENybgi9gc6DnxgB3vyc2LjMc0c/EnXBAQN/dR/B1LUGUpznZXqgZKNXs++M60lYlDe/oj/1v6Rd89c8cY101rxwvg+Krhwj2RoHbxkDFOYVoKVMyjm90AzqvDoNubxxvMYxol0mkuz4N8ZjsRHU1kAcIMADHbSiKXkJ6LJBLELV6KCW4dYEIjUa90fmPi3w+4jZGutmi33Ht6slhvm68/C3pnbk37y3gbIJPC2Md3nqBnivHiuvtvL2Vvn170SUjZ/ccSF3X9fxQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=cornell.edu; dmarc=pass action=none header.from=cornell.edu; dkim=pass header.d=cornell.edu; arc=none Received: from BN7PR04MB4388.namprd04.prod.outlook.com (2603:10b6:406:f8::19) by BN8PR04MB6369.namprd04.prod.outlook.com (2603:10b6:408:7a::24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4457.23; Mon, 30 Aug 2021 02:15:31 +0000 Received: from BN7PR04MB4388.namprd04.prod.outlook.com ([fe80::38bd:b608:234f:9ec6]) by BN7PR04MB4388.namprd04.prod.outlook.com ([fe80::38bd:b608:234f:9ec6%7]) with mapi id 15.20.4457.024; Mon, 30 Aug 2021 02:15:30 +0000 Subject: Re: cygrunsrv + sshd + rsync = 20 times too slow -- throttled? To: cygwin@cygwin.com References: <41A583E1-C8E7-42AB-9F24-EEC33A41EC60@house.org> <20210825201845.07b6400b79dc5558a7761efe@nifty.ne.jp> <20210826062934.54f2f2216021c095bb7ba13b@nifty.ne.jp> <3b560051-ab27-f392-ca4b-d1fd9b5733b0@cornell.edu> <20210827202440.47706fc2fc07c5e9a1bc0047@nifty.ne.jp> <4f2cb5f3-ce9c-c617-f65f-841a5eca096e@cornell.edu> <20210828022111.91ef5b4ff24f6da9fadb489e@nifty.ne.jp> <20210828184102.f2206a8a9e5fe5cf24bf5e45@nifty.ne.jp> <20210829180729.48b4e877f773cb3980c5766d@nifty.ne.jp> <20210830091314.f9a2cb71794d0f68cdb5eba7@nifty.ne.jp> <20210830092259.52f7d54fc3fa340738373af4@nifty.ne.jp> From: Ken Brown Message-ID: Date: Sun, 29 Aug 2021 22:15:29 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 In-Reply-To: <20210830092259.52f7d54fc3fa340738373af4@nifty.ne.jp> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MN2PR14CA0002.namprd14.prod.outlook.com (2603:10b6:208:23e::7) To BN7PR04MB4388.namprd04.prod.outlook.com (2603:10b6:406:f8::19) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [192.168.1.211] (74.69.128.111) by MN2PR14CA0002.namprd14.prod.outlook.com (2603:10b6:208:23e::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4457.17 via Frontend Transport; Mon, 30 Aug 2021 02:15:30 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 1b9d57ed-6373-4e1a-5d7f-08d96b5c0a63 X-MS-TrafficTypeDiagnostic: BN8PR04MB6369: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:4941; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:BN7PR04MB4388.namprd04.prod.outlook.com; PTR:; CAT:NONE; SFS:(4636009)(346002)(396003)(376002)(39860400002)(366004)(136003)(8936002)(38100700002)(6486002)(5660300002)(75432002)(86362001)(36756003)(31696002)(66556008)(66476007)(66946007)(786003)(478600001)(16576012)(2906002)(2616005)(26005)(8676002)(956004)(6916009)(83380400001)(31686004)(53546011)(186003)(316002)(43740500002)(45980500001); DIR:OUT; SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?Windows-1252?Q?ntbDg0Q3NE67R8amI8gYH9mSrzTcx6AgOB20arJmLnPO8CG4lg1Lzh0L?= =?Windows-1252?Q?SEGj0/O1ZEPWhEXO6mqUmv1obWIf1gAWtd2wNZ0laB5TwTn19gPnUaYA?= =?Windows-1252?Q?Pentc3QxdmNm88mX6Zs0w44ILS6xPetq9HkOJ1RcTjRtCEIYAaaN0jAH?= =?Windows-1252?Q?MFAJFV1I8R5EM1VChG2mMayzE+s14I0ozBxxqjBH1ZCLqMTDU3/4HnA2?= =?Windows-1252?Q?iIS/zMpEhZHtraETiqabYcc4vPvgE0Mp1jq7OhPelmf6F5lUKYG/hxjI?= =?Windows-1252?Q?2SXa/aVCpHk1Nwb3ZUvGt4r4ShxoKb/hgpltma0nLSU6InF3CIiwflSX?= =?Windows-1252?Q?DG/djIZi1CSvuVUASdDAHNVqU+ikWh0qFOrpZqZXpBRJgAnLC9jVXhf+?= =?Windows-1252?Q?xZ9gfvUZeky7uNnZpBHaEn5Hlleos3r0k74QNWslgPFr9VL9tNiwh/Yi?= =?Windows-1252?Q?eY54OGocyEA9oOUR0eKn8FIGzGFQQndH9UppZUCveP8dGpZDIso6QqhH?= =?Windows-1252?Q?Vu1TWMXQPAu3P1Wve+M75JCpVg/VD9aOHIlz5J7k1rfg0teERGTzhm4q?= =?Windows-1252?Q?pujI5Y6ojXWlztiXukiArmGD/MzjIBJCAkcC/3LGKdJoknSpf3Zv/cYa?= =?Windows-1252?Q?K32U7b5wkMPQFyzYSgISTGDJ1phR/JiyNCSg1LFp0iQwYvpRM4N1Ju5i?= =?Windows-1252?Q?ZQPFVy4aUFExJyKaoG2g/htnmOXgSUL8f9SygYYqy3ilV+SPKBOdILbu?= =?Windows-1252?Q?Zw5KdG2Ru+UYSyfLO8XtGS3mfAzoJgpRrnqpNBn041MjtvF9owxM1wyH?= =?Windows-1252?Q?e/B0gYoJWdqlTYn3H5BmIXfU3kLO+/Wyo5BTPaAYwSt8nYozv/uU4HZV?= =?Windows-1252?Q?FZyGlb4ZpLWr2pp/haEpuqfjaPg8UFD4WlSsVhSwnCQCuA3HKn/57SZX?= =?Windows-1252?Q?aeCLSMq1FFqJBlyBe0jLuCJfrTS9QlJ0b2NGQkw3NUXhljV7PFwLlMuV?= =?Windows-1252?Q?PDr+sadM2tGXORGGQow8ofhEU+1fjaCnteZO7CvZDfOylBKGWJBYa8eo?= =?Windows-1252?Q?oylTkNpMnYzQMQoeBZrjWnCTeS1rwk8Xhf3Ko6Bo8KaIvpN6yMr0LLyA?= =?Windows-1252?Q?SFHpXqKVbt1VZb748mq4QQOHtT2R+X7lsAg1hxh8951OIQMJ7uVnwp0S?= =?Windows-1252?Q?bjiKu2nfExnQXUKSqkBI5jVXyExKz7hjMIGQ1sRfPgViGElkvr1p7PU+?= =?Windows-1252?Q?uilAF8TwkdBQQ8SYTTMm9UQQVYSKu698Wkyyc/Gcq/jfSvdOOi86kgLW?= =?Windows-1252?Q?bOM0O44jFyaQ49cgw5Lvwy+5sg591w8pz708OVTFmIXTHdWn4heiZsxo?= =?Windows-1252?Q?DRgrd+jzODfqGKnbz7/1/iuW4GEEBVs1PV3qWzi54Bmks1Xkm450njCn?= X-OriginatorOrg: cornell.edu X-MS-Exchange-CrossTenant-Network-Message-Id: 1b9d57ed-6373-4e1a-5d7f-08d96b5c0a63 X-MS-Exchange-CrossTenant-AuthSource: BN7PR04MB4388.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Aug 2021 02:15:30.6302 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 5d7e4366-1b9b-45cf-8e79-b14b27df46e1 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 8rBJ6lGGlTTuqlqEb4WmzlW2KkOM4CGuOZWYAaDbruDCblp3+pT2BYbFt8XXH46GsZP/0n0W6vfc67inUDhnFQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN8PR04MB6369 X-Spam-Status: No, score=-9.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, JMQ_SPF_NEUTRAL, MSGID_FROM_MTA_HEADER, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_PASS, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: cygwin@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 30 Aug 2021 02:15:43 -0000 On 8/29/2021 8:22 PM, Takashi Yano via Cygwin wrote: > On Mon, 30 Aug 2021 09:13:14 +0900 > Takashi Yano wrote: >> On Sun, 29 Aug 2021 17:04:56 -0400 >> Ken Brown wrote: >>> On 8/29/2021 5:07 AM, Takashi Yano via Cygwin wrote: >>>> On Sat, 28 Aug 2021 18:41:02 +0900 >>>> Takashi Yano wrote: >>>>> On Sat, 28 Aug 2021 10:43:27 +0200 >>>>> Corinna Vinschen wrote: >>>>>> On Aug 28 02:21, Takashi Yano via Cygwin wrote: >>>>>>> On Fri, 27 Aug 2021 12:00:50 -0400 >>>>>>> Ken Brown wrote: >>>>>>>> Two years ago I thought I needed nt_create to avoid problems when calling >>>>>>>> set_pipe_non_blocking. Are you saying that's not an issue? Is >>>>>>>> set_pipe_non_blocking unnecessary? Is that the point of your modification to >>>>>>>> raw_read? >>>>>>> >>>>>>> Yes. Instead of making windows read function itself non-blocking, >>>>>>> it is possible to check if the pipe can be read before read using >>>>>>> PeekNamedPipe(). If the pipe cannot be read right now, EAGAIN is >>>>>>> returned. >>>>>> >>>>>> The problem is this: >>>>>> >>>>>> if (PeekNamedPipe()) >>>>>> ReadFile(blocking); >>>>>> >>>>>> is not atomic. I. e., if PeekNamedPipe succeeds, nothing keeps another >>>>>> thread from draining the pipe between the PeekNamedPipe and the ReadFile >>>>>> call. And as soon as ReadFile runs, it hangs indefinitely and we can't >>>>>> stop it via a signal. >>>>> >>>>> Hmm, you are right. Mutex guard seems to be necessary like pty code >>>>> if we go this way. >>>> >>>> I have found that set_pipe_non_blocking() succeeds for both read and >>>> write pipes if the write pipe is created by CreateNamedPipe() and the >>>> read pipe is created by CreateFile() contrary to the current create() >>>> code. Therefore, not only nt_create() but also PeekNamedPipe() become >>>> unnecessary. >>>> >>>> Please see the revised patch attached. >>> >>> I haven't had a chance to test this myself yet, but occurs to me that we might >>> have a different problem after this patch: Does the write handle that we get >>> from CreateNamedPipe() have FILE_READ_ATTRIBUTES access? >> >> I have just checked this, and the answer is "No". Due to this problem, >> NtQueryInformationFile() call in select() fails on the write pipe. >> >> It seems that we need more consideration... > > We have two easy options: > 1) Configure the pipe with PIPE_ACCESS_DUPLEX. > 2) Use nt_create() again and forget C# program issue. I vote for 2), but let's see what Corinna thinks. > Even without this problem, select() for writing pipe has a bug > and does not wrok as expected. The following patch seems to be > needed. > > diff --git a/winsup/cygwin/select.cc b/winsup/cygwin/select.cc > index 83e1c00e0..ac2fd227e 100644 > --- a/winsup/cygwin/select.cc > +++ b/winsup/cygwin/select.cc > @@ -612,7 +612,6 @@ pipe_data_available (int fd, fhandler_base *fh, HANDLE h, bool writing) > that. This means that a pipe could still block since you could > be trying to write more to the pipe than is available in the > buffer but that is the hazard of select(). */ > - fpli.WriteQuotaAvailable = fpli.OutboundQuota - fpli.ReadDataAvailable; > if (fpli.WriteQuotaAvailable > 0) > { > paranoid_printf ("fd %d, %s, write: size %u, avail %u", fd, > I agree. Ken