From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by dpdk.org (Postfix) with ESMTP id A7ECC1B4DC for ; Tue, 26 Jun 2018 11:44:26 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Jun 2018 02:44:25 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,274,1526367600"; d="scan'208";a="51967366" Received: from fmsmsx103.amr.corp.intel.com ([10.18.124.201]) by orsmga007.jf.intel.com with ESMTP; 26 Jun 2018 02:44:20 -0700 Received: from fmsmsx102.amr.corp.intel.com (10.18.124.200) by FMSMSX103.amr.corp.intel.com (10.18.124.201) with Microsoft SMTP Server (TLS) id 14.3.319.2; Tue, 26 Jun 2018 02:44:18 -0700 Received: from shsmsx104.ccr.corp.intel.com (10.239.4.70) by FMSMSX102.amr.corp.intel.com (10.18.124.200) with Microsoft SMTP Server (TLS) id 14.3.319.2; Tue, 26 Jun 2018 02:44:17 -0700 Received: from shsmsx103.ccr.corp.intel.com ([169.254.4.51]) by SHSMSX104.ccr.corp.intel.com ([169.254.5.87]) with mapi id 14.03.0319.002; Tue, 26 Jun 2018 17:44:15 +0800 From: "Zhang, Qi Z" To: Thomas Monjalon , "Burakov, Anatoly" CC: "Ananyev, Konstantin" , "dev@dpdk.org" , "Richardson, Bruce" , "Yigit, Ferruh" , "Shelton, Benjamin H" , "Vangati, Narender" Thread-Topic: [PATCH v4 05/24] eal: support mp task be invoked in a separate task Thread-Index: AQHUDRx2w2sRj5n0/UiP7cvYpzIxS6RxuJUAgAAGAACAAItP4A== Date: Tue, 26 Jun 2018 09:44:15 +0000 Message-ID: <039ED4275CED7440929022BC67E706115323E58B@SHSMSX103.ccr.corp.intel.com> References: <20180607123849.14439-1-qi.z.zhang@intel.com> <20180626070832.3055-6-qi.z.zhang@intel.com> <167506ed-380a-898e-2f52-20be0178a49b@intel.com> <3228714.zAXYVjxDgJ@xps> In-Reply-To: <3228714.zAXYVjxDgJ@xps> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYzMyYzdjNjQtZmYwOS00MDQ5LWFiODAtZGM3NTZjYTUyN2NkIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjEwLjE4MDQuNDkiLCJUcnVzdGVkTGFiZWxIYXNoIjoiWFp0V2ZOSkdmM2FqeVdseWRYbkFhcFwvZzdIazh4Zk9yWWhWbzFWQTVOYjNxQklZdWI1RFZYcm92RXVcL2NOVUhWIn0= x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.200.100 dlp-reaction: no-action x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH v4 05/24] eal: support mp task be invoked in a separate task X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 Jun 2018 09:44:27 -0000 > -----Original Message----- > From: Thomas Monjalon [mailto:thomas@monjalon.net] > Sent: Tuesday, June 26, 2018 5:24 PM > To: Burakov, Anatoly > Cc: Zhang, Qi Z ; Ananyev, Konstantin > ; dev@dpdk.org; Richardson, Bruce > ; Yigit, Ferruh ; She= lton, > Benjamin H ; Vangati, Narender > > Subject: Re: [PATCH v4 05/24] eal: support mp task be invoked in a separa= te > task >=20 > 26/06/2018 11:02, Burakov, Anatoly: > > On 26-Jun-18 8:08 AM, Qi Zhang wrote: > > > We know the limitation that sync IPC can't be invoked in mp handler > > > itself which will cause deadlock, the patch introduce new API > > > rte_eal_mp_task_add to support mp handler be delegated in a separate > > > task. > > > > > > Signed-off-by: Qi Zhang > > > --- > > > > I would really like to find another solution to this problem. Creating > > a new thread per hotplug request seems like an overkill - even more so > > than having two threads. Creating a new thread potentially while the > > application is working may have other implications (e.g. there's a > > non-zero amount of time between thread created and thread affinitized, > > which may disrupt hotpaths). > > > > It seems to me that the better solution would've been to leave the IPC > > thread in place. There are two IPC threads in the first place because > > there was a circular dependency between rte_malloc and alarm API. My > > patch fixes that - so how about we remove *one* IPC thread, but leave > > the other one in place? > > > > Thomas, any thoughts? (quick description - hotplug needs IPC, and > > hotplug may need to allocate memory, which also needs IPC, which will > > cause a deadlock if IPC is one thread) >=20 > We can keep one IPC thread until we find a better solution. >=20 >=20 OK, then I will delegate the task to interrupt thread and remove the tempor= al thread solution. Thanks Qi >=20