From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932122AbcF1Kvt (ORCPT ); Tue, 28 Jun 2016 06:51:49 -0400 Received: from mail-bl2on0137.outbound.protection.outlook.com ([65.55.169.137]:30240 "EHLO na01-bl2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752729AbcF1Kdd convert rfc822-to-8bit (ORCPT ); Tue, 28 Jun 2016 06:33:33 -0400 From: Dexuan Cui To: David Miller CC: "gregkh@linuxfoundation.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "devel@linuxdriverproject.org" , "olaf@aepfle.de" , "apw@canonical.com" , "jasowang@redhat.com" , "vkuznets@redhat.com" , "cavery@redhat.com" , KY Srinivasan , Haiyang Zhang , "joe@perches.com" Subject: RE: [PATCH v12 net-next 1/1] hv_sock: introduce Hyper-V Sockets Thread-Topic: [PATCH v12 net-next 1/1] hv_sock: introduce Hyper-V Sockets Thread-Index: AdHN7DXkHulf2AsUS1CUMikXhkJOLQDM/dsAAAAk7QA= Date: Tue, 28 Jun 2016 09:59:21 +0000 Message-ID: References: <20160628.053350.1891488485477523405.davem@davemloft.net> In-Reply-To: <20160628.053350.1891488485477523405.davem@davemloft.net> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: spf=none (sender IP is ) smtp.mailfrom=decui@microsoft.com; x-originating-ip: [2404:f801:9000:19::83] x-ms-office365-filtering-correlation-id: 84c4d7f4-f17f-4bb7-5330-08d39f3ae088 x-microsoft-exchange-diagnostics: 1;CO2PR03MB2278;6:JIT5zqKa2ku1ISfWq4k5ZUWrzYXxsKvGI/myb3ah7vxLr9EaHstvxzj8fWMTc7Pv5gxhr6Ni8N97XfX3+w7gNO3MvQsP9L0SYqcGyh3CwXPtzOjI9W99FaMFB/gmSVnO6YAwKrJwjNYRW/wz7CyWYEteiw9293Qwl/8LEPg4/Xy7h9jxpIV0iogGVtYoEBgm0YUNEipveHliW6kOHbSp7plOk3SnyVk220uWLUurTNoQIKAL/PFiQTtDjm3m0a7wJXKFyhKzMc6txj2zwuoyvJeAscVXNYKauou2ZI3XeneqQ6bPYP7FWKwwKbmZpR/kE8eJgNoPg4LrdQGXpWwUAg==;5:ltz5W5AlUr0qLnSgyn2116BdqoPhf8tH38B8PrGPFUWaNK2Ikzg3nRmvWDegpNG/zyz2BB/VMUAhv3M6FiB0A83yPEDX2ExtKOohHUITsZT8AR/zVZijPc1fREDfJauoL2vLmJpd9xO2KvLs88NI/Q==;24:7hBswqJerwnIt7681NLL/DzIP2gsJUvHsOgGXPo+7RhchUgoKoXrTJt/RuAvg1oafsVKtzNIE1KgFjhzMpCgBgaNhgjDxlPOwE7xX9YW+U4=;7:F9ybyd7hozbGTL3Zv89tgoihflyYJ7topvzPbVTeaZ3WD0TdyeZbSgGNQlUKVPjYL/SUqH6c3pe2IHhORRq0eKcl0zlgWcLHZ/47TLvLW+iYuB/VCYMRtM0bXBhqwaIkgCYt5G47DPRg2evG68+TC0ja6x0Mrhrt5CIiqkC1OvMdq7bwAgU9GRykM5HqfFMs3K3ftcQWvnHnHf1xryBnrAXzw6osRGjLVonervXoErX3z4U7gJ43lPrnjkD5GbEy x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:CO2PR03MB2278; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(9452136761055)(198206253151910); x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(61425038)(601004)(2401047)(5005006)(8121501046)(3002001)(10201501046)(6055026)(61426038)(61427038);SRVR:CO2PR03MB2278;BCL:0;PCL:0;RULEID:;SRVR:CO2PR03MB2278; x-forefront-prvs: 0987ACA2E2 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(6009001)(7916002)(189002)(199003)(5002640100001)(8990500004)(10290500002)(77096005)(110136002)(10400500002)(92566002)(11100500001)(5005710100001)(76176999)(9686002)(97736004)(102836003)(189998001)(19580405001)(19580395003)(68736007)(6116002)(586003)(54356999)(7846002)(5003600100003)(7696003)(50986999)(305945005)(7736002)(122556002)(10090500001)(8936002)(86362001)(2900100001)(4326007)(2906002)(3280700002)(3660700001)(99286002)(87936001)(8676002)(2950100001)(81166006)(81156014)(74316001)(105586002)(101416001)(76576001)(86612001)(106356001)(33656002)(3826002);DIR:OUT;SFP:1102;SCL:1;SRVR:CO2PR03MB2278;H:CO2PR03MB2182.namprd03.prod.outlook.com;FPR:;SPF:None;PTR:InfoNoRecords;MX:1;A:1;LANG:en; spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-originalarrivaltime: 28 Jun 2016 09:59:21.2161 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO2PR03MB2278 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > From: David Miller [mailto:davem@davemloft.net] > Sent: Tuesday, June 28, 2016 17:34 > To: Dexuan Cui > Cc: gregkh@linuxfoundation.org; netdev@vger.kernel.org; linux- > kernel@vger.kernel.org; devel@linuxdriverproject.org; olaf@aepfle.de; > apw@canonical.com; jasowang@redhat.com; vkuznets@redhat.com; > cavery@redhat.com; KY Srinivasan ; Haiyang Zhang > ; joe@perches.com > Subject: Re: [PATCH v12 net-next 1/1] hv_sock: introduce Hyper-V Sockets > > From: Dexuan Cui > Date: Fri, 24 Jun 2016 07:45:24 +0000 > > > + while ((ret = vmalloc(size)) == NULL) > > + ssleep(1); > > This is completely, and entirely, unacceptable. > > If the allocation fails, you return an error and release > your resources. > > You don't just loop forever waiting for it to succeed. Hi David, I agree this is ugly... The idea here is: IMO the syscalls sys_read()/write() shoudn't return -ENOMEM, so I have to make sure the buffer allocation succeeds? I tried to use kmalloc with __GFP_NOFAIL, but I hit a warning in in mm/page_alloc.c: WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); What error code do you think I should return? EAGAIN, ERESTARTSYS, or something else? May I have your suggestion? Thanks! -- Dexuan