From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 75836DD2 for ; Thu, 25 Jan 2018 12:09:11 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Jan 2018 03:09:08 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,411,1511856000"; d="scan'208";a="169037375" Received: from irsmsx109.ger.corp.intel.com ([163.33.3.23]) by orsmga004.jf.intel.com with ESMTP; 25 Jan 2018 03:09:07 -0800 Received: from irsmsx112.ger.corp.intel.com (10.108.20.5) by IRSMSX109.ger.corp.intel.com (163.33.3.23) with Microsoft SMTP Server (TLS) id 14.3.319.2; Thu, 25 Jan 2018 11:09:06 +0000 Received: from irsmsx105.ger.corp.intel.com ([169.254.7.236]) by irsmsx112.ger.corp.intel.com ([169.254.1.12]) with mapi id 14.03.0319.002; Thu, 25 Jan 2018 11:09:06 +0000 From: "Ananyev, Konstantin" To: Thomas Monjalon CC: Matan Azrad , =?iso-8859-1?Q?Ga=EBtan_Rivet?= , "Wu, Jingjing" , "dev@dpdk.org" , Neil Horman , "Richardson, Bruce" Thread-Topic: [dpdk-dev] [PATCH v3 7/7] app/testpmd: adjust ethdev port ownership Thread-Index: AQHTlHB0mIDt6Y+2sU2Ne78ePy1VDqOB9FHwgAC4R4CAAKpZAIABFicAgAAC8cA= Date: Thu, 25 Jan 2018 11:09:05 +0000 Message-ID: <2601191342CEEE43887BDE71AB977258862835EB@irsmsx105.ger.corp.intel.com> References: <1515318351-4756-1-git-send-email-matan@mellanox.com> <1682675.gfxK9aSxec@xps> <2601191342CEEE43887BDE71AB9772588628308D@irsmsx105.ger.corp.intel.com> <42152390.b8nyHhbJZJ@xps> In-Reply-To: <42152390.b8nyHhbJZJ@xps> Accept-Language: en-IE, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYzNjMDVhNzItNGYyOC00YTdkLWEzOTUtMGM4OGYzYmZlNjJiIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE2LjUuOS4zIiwiVHJ1c3RlZExhYmVsSGFzaCI6ImJoWVkyYkZ3T3lcL2pTT0E4cFg2dEF3VWtCN05CRnRWcVFEWkxvcHVpZHJZPSJ9 x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.0.116 dlp-reaction: no-action x-originating-ip: [163.33.239.181] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH v3 7/7] app/testpmd: adjust ethdev port ownership 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: Thu, 25 Jan 2018 11:09:12 -0000 > -----Original Message----- > From: Thomas Monjalon [mailto:thomas@monjalon.net] > Sent: Thursday, January 25, 2018 10:55 AM > To: Ananyev, Konstantin > Cc: Matan Azrad ; Ga=EBtan Rivet ; Wu, Jingjing ; > dev@dpdk.org; Neil Horman ; Richardson, Bruce > Subject: Re: [dpdk-dev] [PATCH v3 7/7] app/testpmd: adjust ethdev port ow= nership >=20 > 24/01/2018 19:30, Ananyev, Konstantin: > > From: Thomas Monjalon [mailto:thomas@monjalon.net] > > > 23/01/2018 22:18, Ananyev, Konstantin: > > > > > > > > > > 23/01/2018 16:18, Ananyev, Konstantin: > > > > > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Ananyev, K= onstantin > > > > > > > From: Thomas Monjalon [mailto:thomas@monjalon.net] > > > > > > > > 23/01/2018 14:34, Ananyev, Konstantin: > > > > > > > > > If that' s the use case, then I think you need to set dev= ice ownership at creation time - > > > > > > > > > inside dev_allocate(). > > > > > > > > > Again that would avoid such racing conditions inside test= pmd. > > > > > > > > > > > > > > > > The devices must be allocated at a low level layer. > > > > > > > > > > > > > > No one arguing about that. > > > > > > > But we can provide owner id information to the low level. > > > > > > > > > > Sorry, you did not get it. > > > > > > > > Might be. > > > > > > > > > We cannot provide owner id at the low level > > > > > because it is not yet decided who will be the owner > > > > > before the port is allocated. > > > > > > > > Why is that? > > > > What prevents us decide who will manage that device *before* alloca= ting port of it? > > > > IMO we do have all needed information at that stage. > > > > > > We don't have the information. > > > > At that point we do have dev name and all parameters, right? >=20 > We just have the PCI id. >=20 > > Plus we do have blacklist/whitelist, etc. > > So what else are we missing to make the decision at that point? >=20 > It depends on the ownership policy. > Example: we can decide to take ownership based on a MAC address. That's sounds a bit articificial (mac address can be changed on the fly), b= ut ok - for such devices user can decide to use default id first and change it later after port is allocated and dev_init() is passed. Though as I understand there situations (like in failsafe PMD) when we do=20 know for sure owner_id before calling dev_allocate(). > Another example: it can be decided to take ownership of a given driver. > We don't have these informations with the PCI id. >=20 > > > It is a new device, it is matched by a driver which allocates a port. > > > I don't see where the higher level can interact here. > > > And even if you manage a trick, the higher level needs to read the po= rt > > > informations to decide the ownership. > > > > Could you specify what particular port information it needs? >=20 > Replied to the same question above :) >=20 >=20 > > > > > > > > When a new device appears (hotplug), an ethdev port should = be allocated > > > > > > > > automatically if it passes the whitelist/blacklist policy t= est. > > > > > > > > Then we must decide who will manage this device. > > > > > > > > I suggest notifying the DPDK libs first. > > > > > > > > So a DPDK lib or PMD like failsafe can have the priority to= take the > > > > > > > > ownership in its notification callback. > > > > > > > > > > > > > > Possible, but seems a bit overcomplicated. > > > > > > > Why not just: > > > > > > > > > > > > > > Have a global variable process_default_owner_id, that would b= e init once at startup. > > > > > > > Have an LTS variable default_owner_id. > > > > > > > It will be used by rte_eth_dev_allocate() caller can set dev-= >owner_id at creation time, > > > > > > > so port allocation and setting ownership - will be an atomic = operation. > > > > > > > At the exit rte_eth_dev_allocate() will always reset default_= owner_id=3D0: > > > > > > > > > > > > > > rte_eth_dev_allocate(...) > > > > > > > { > > > > > > > lock(owner_lock); > > > > > > > > > > > > > > owner =3D RTE_PER_LCORE(default_owner_id); > > > > > > > if (owner =3D=3D 0) > > > > > > > owner =3D process_default_owner_id; > > > > > > > set_owner(port, ..., owner); > > > > > > > unlock(owner_lock); > > > > > > > RTE_PER_LCORE(default_owner_id) =3D 0; > > > > > > > > > > > > Or probably better to leave default_owner_id reset to the calle= r. > > > > > > Another thing - we can use same LTS variable in all control ops= to > > > > > > allow/disallow changing of port configuration based on ownershi= p. > > > > > > Konstantin > > > > > > > > > > > > > } > > > > > > > > > > > > > > So callers who don't need any special ownership - don't need = to do anything. > > > > > > > Special callers (like failsafe) can set default_owenr_id just= before calling hotplug > > > > > > > handling routine. > > > > > > > > > > No, hotplug will not be a routine. > > > > > I am talking about real hotplug, like a device which appears in t= he VM. > > > > > This new device must be handled by EAL and probed automatically i= f > > > > > comply with whitelist/blacklist policy given by the application o= r user. > > > > > Real hotplug is asynchronous. > > > > > > > > By 'asynchronous' here you mean it would be handled in the EAL inte= rrupt thread > > > > or something different? > > > > > > Yes, we receive an hotplug event which is processed in the event thre= ad. > > > > > > > Anyway, I suppose you do need a function inside DPDK that will do = the actual work in response > > > > on hotplug event, right? > > > > > > Yes > > > > Ok, btw why that function has to be always called from interrupt thread= ? > > Why not to allow user to decide? >=20 > Absolutely, the user must decide. > In the example of failsafe, the user instructs a policy to decide > which devices will be owned, so failsafe takes the decision based > on user inputs. >=20 > > Some apps have their own thread dedicated for control ops (like testpmd= ) > > For them it might be plausible to call that function from their own con= trol thread context. > > Konstantin > > > > > > > > > That's what I refer to as 'hotplug routine' above. > > > > > > > > > We will just receive notifications that it appeared. > > > > > > > > > > Note: there is some temporary code in failsafe to manage some hot= plug. > > > > > This code must be removed when it will be properly handled in EAL= . > > > > > > > > Ok, if it is just a temporary code, that would be removed soon - > > > > then it definitely seems wrong to modify tespmd (or any other user = app) > > > > to comply with that temporary solution. > > > > > > It will be modified when EAL hotplug will be implemented. > > > > > > However, the ownership issue will be the same: > > > we don't know the owner when allocating a port.