From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <harry.van.haaren@intel.com> Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by dpdk.org (Postfix) with ESMTP id DB0432C18 for <dev@dpdk.org>; Wed, 28 Mar 2018 10:22:44 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Mar 2018 01:22:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,370,1517904000"; d="scan'208";a="215547138" Received: from irsmsx109.ger.corp.intel.com ([163.33.3.23]) by fmsmga005.fm.intel.com with ESMTP; 28 Mar 2018 01:22:42 -0700 Received: from irsmsx101.ger.corp.intel.com ([169.254.1.176]) by IRSMSX109.ger.corp.intel.com ([169.254.13.170]) with mapi id 14.03.0319.002; Wed, 28 Mar 2018 09:22:41 +0100 From: "Van Haaren, Harry" <harry.van.haaren@intel.com> To: Thomas Monjalon <thomas@monjalon.net>, "Tan, Jianfeng" <jianfeng.tan@intel.com> CC: "Burakov, Anatoly" <anatoly.burakov@intel.com>, "dev@dpdk.org" <dev@dpdk.org>, "Ananyev, Konstantin" <konstantin.ananyev@intel.com> Thread-Topic: [dpdk-dev] [PATCH v6 2/2] eal: add asynchronous request API to DPDK IPC Thread-Index: AQHTxel7DHKbmMO08ke0/uE2vr7zt6Pk1t0AgABZl4CAABvcYA== Date: Wed, 28 Mar 2018 08:22:41 +0000 Message-ID: <E923DB57A917B54B9182A2E928D00FA65E018297@IRSMSX101.ger.corp.intel.com> References: <cde1ac06bc0f7e6193df6582d8b8a3b62fe51d09.1522159146.git.anatoly.burakov@intel.com> <3396888.LEadjR7LpM@xps> <ED26CBA2FAD1BF48A8719AEF02201E36514A9BC0@SHSMSX103.ccr.corp.intel.com> <2563064.olffpIeeN1@xps> In-Reply-To: <2563064.olffpIeeN1@xps> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYjNjMmIwN2QtM2E3OS00Y2Q2LTkzZGYtNmU0Y2FmOGRhMjliIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjIuNS4xOCIsIlRydXN0ZWRMYWJlbEhhc2giOiJ6dzRhNVRpN0hGQ0tOZWRvZVozS0RvTnN1MStCOHdHbDF6NlBnV1kwek9KZHd1RDlud0FqYVNUMmdaWlc0UXVUIn0= x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.200.100 dlp-reaction: no-action x-originating-ip: [163.33.239.182] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH v6 2/2] eal: add asynchronous request API to DPDK IPC X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <https://dpdk.org/ml/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://dpdk.org/ml/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <https://dpdk.org/ml/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> X-List-Received-Date: Wed, 28 Mar 2018 08:22:45 -0000 > From: Thomas Monjalon [mailto:thomas@monjalon.net] > Sent: Wednesday, March 28, 2018 8:30 AM > To: Tan, Jianfeng <jianfeng.tan@intel.com> > Cc: Burakov, Anatoly <anatoly.burakov@intel.com>; dev@dpdk.org; Ananyev, > Konstantin <konstantin.ananyev@intel.com>; Van Haaren, Harry > <harry.van.haaren@intel.com> > Subject: Re: [dpdk-dev] [PATCH v6 2/2] eal: add asynchronous request API = to > DPDK IPC >=20 > 28/03/2018 04:08, Tan, Jianfeng: > > Hi Thomas , > > > > From: Thomas Monjalon [mailto:thomas@monjalon.net] > > > 27/03/2018 15:59, Anatoly Burakov: > > > > Under the hood, we create a separate thread to deal with replies to > > > > asynchronous requests, that will just wait to be notified by the > > > > main thread, or woken up on a timer. > > > > > > I really don't like that a library is creating a thread. > > > We don't even know where the thread is created (which core). > > > Can it be a rte_service? or in the interrupt thread? > > > > Agree that we'd better not adding so many threads in a library. > > > > I was considering to merge all the threads into the interrupt thread, > however, we don't have an interrupt thread in freebsd. Further, we don't > implement alarm API in freebsd. That's why I tend to current implementati= on, > and optimize it later. >=20 > I would prefer we improve the current code now instead of polluting more > with more uncontrolled threads. >=20 > > For rte_service, it may be not a good idea to reply on it as it needs > explicit API calls to setup. >=20 > I don't see the issue of the explicit API. > The IPC is a new service. Although I do like to see new services, if we want to enable "core" dpdk fu= nctionality with Services, we need a proper designed solution for that. Ser= vice cores is not intended for "occasional" work - there is no method to bl= ock and sleep on a specific service until work becomes available, so this w= ould imply a busy-polling. Using a service (hence busy polling) for rte_mal= loc()-based memory mapping requests is inefficient, and total overkill :) For this patch I suggest to use some blocking-read capable mechanism. The above said, in the longer term it would be good to have a design that a= llows new file-descriptors to be added to a "dpdk core" thread, which perfo= rms occasional lengthy work if the FD has data available.