From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from jaguar.aricent.com (jaguar.aricent.com [121.241.96.11]) by dpdk.org (Postfix) with ESMTP id E9C81DE0 for ; Mon, 25 Nov 2013 14:57:13 +0100 (CET) Received: from jaguar.aricent.com (localhost [127.0.0.1]) by postfix.imss71 (Postfix) with ESMTP id 6508F36B65; Mon, 25 Nov 2013 19:27:54 +0530 (IST) Received: from GUREXHT01.ASIAN.AD.ARICENT.COM (gurexht01.asian.ad.aricent.com [10.203.171.136]) by jaguar.aricent.com (Postfix) with ESMTP id 4B73436B55; Mon, 25 Nov 2013 19:27:54 +0530 (IST) Received: from GUREXMB01.asian.ad.aricent.com ([10.203.171.134]) by GUREXHT01.ASIAN.AD.ARICENT.COM ([10.203.171.136]) with mapi; Mon, 25 Nov 2013 19:27:54 +0530 From: Prashant Upadhyaya To: "Richardson, Bruce" , "dev@dpdk.org" Date: Mon, 25 Nov 2013 19:27:53 +0530 Thread-Topic: Query regarding multiple processes in DPDK Thread-Index: Ac7nf/izY2xhv9ftQ/6e54GzBsCm/QABo68QAABRxpAAAFXlQACCerVAAAthgQAACWm64A== Message-ID: References: <59AF69C657FD0841A61C55336867B5B01A976C1F@IRSMSX103.ger.corp.intel.com> <59AF69C657FD0841A61C55336867B5B01A977283@IRSMSX103.ger.corp.intel.com> In-Reply-To: <59AF69C657FD0841A61C55336867B5B01A977283@IRSMSX103.ger.corp.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-TM-AS-MML: No Subject: Re: [dpdk-dev] Query regarding multiple processes in DPDK X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 25 Nov 2013 13:57:14 -0000 Hi Bruce, Thanks, this was very useful information. Regards -Prashant -----Original Message----- From: Richardson, Bruce [mailto:bruce.richardson@intel.com] Sent: Monday, November 25, 2013 2:59 PM To: Prashant Upadhyaya; dev@dpdk.org Subject: RE: Query regarding multiple processes in DPDK If the primary process dies: a) The memory does not go away, so the second process can still use it b) When restarting the primary process, you should restart it as a secondar= y one, to ensure it reattaches to memory properly instead of trying to re-i= nitialize it. Regards /Bruce > -----Original Message----- > From: Prashant Upadhyaya [mailto:prashant.upadhyaya@aricent.com] > Sent: Monday, November 25, 2013 4:08 AM > To: Richardson, Bruce; dev@dpdk.org > Subject: RE: Query regarding multiple processes in DPDK > > Hi Bruce, > > One more question -- > > Suppose the first instance comes up as primary and creates the mbuf > pool and rings etc. [ok] Now, the second instance comes up as > secondary and does the corresponding lookup functions [ok] Now the > primary exits -- at this point can the secondary still run with all > the memory to which it had done the lookup intact, or does the fact > that primary died will lead to all the memory also taken away with it > so that the secondary can no longer function now ? > > Regards > -Prashant > > > -----Original Message----- > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Prashant > Upadhyaya > Sent: Friday, November 22, 2013 7:16 PM > To: Richardson, Bruce; dev@dpdk.org > Subject: Re: [dpdk-dev] Query regarding multiple processes in DPDK > > Thanks Bruce, I think your suggested example of multi_process answers > my questions. > > Regards > -Prashant > > > -----Original Message----- > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Prashant > Upadhyaya > Sent: Friday, November 22, 2013 7:10 PM > To: Richardson, Bruce; dev@dpdk.org > Subject: Re: [dpdk-dev] Query regarding multiple processes in DPDK > > Hi Bruce, > > Thanks. > > Regarding your comment -- > [BR] It will depend upon the application, but in most cases you > probably want to have slightly different code paths for primary and > secondary instances. For example, if a process is running as primary > instance, it will probably call rte_mempool_create or rte_ring_create. > A secondary instance which wants to use these should instead call > rte_mempool_lookup and rte_ring_lookup instead. > For an example of how to write the one binary to be used as both > primary and secondary process, I suggest looking at the symmetric_mp > example application in the examples/multi_process/ directory. > > I was really hoping that the --proc-type=3Dauto, would make the DPDK > libraries internally resolving all this stuff, is that not the case ? > I have not started reading the code for all this yet. > I must launch the same executable twice in my usecase. Even if the > executable code has to make different calls when it comes up as > secondary, is there a way for the usercode to know that it has really > come up as secondary when the --proc-type=3Dauto is used ? > > Regards > -Prashant > > -----Original Message----- > From: Richardson, Bruce [mailto:bruce.richardson@intel.com] > Sent: Friday, November 22, 2013 7:02 PM > To: Prashant Upadhyaya; dev@dpdk.org > Subject: RE: Query regarding multiple processes in DPDK > > Hi Prashant > > > =3D=3D=3D > > The EAL also supports an auto-detection mode (set by EAL > > --proc-type=3Dauto flag), whereby an Intel(r) DPDK process is started > > as a secondary instance if a primary instance is already running. > > =3D=3D=3D > > > > So does this mean that if I have a DPDK exe foo.out, then when I run > > the first instance of foo.out with -proc-type =3D auto, then foo.out > > will run as a primary process and when I spawn the second instance > > of foo.out (with first already running) again with -proc-type=3Dauto, > > then this second instance automatically becomes secondary ? > [BR] Yes, that is the idea. > > > > > Also is there any user code initialization change required or > > exactly the same code will work for both the processes ? > [BR] It will depend upon the application, but in most cases you > probably want to have slightly different code paths for primary and > secondary instances. For example, if a process is running as primary > instance, it will probably call rte_mempool_create or rte_ring_create. > A secondary instance which wants to use these should instead call > rte_mempool_lookup and rte_ring_lookup instead. > For an example of how to write the one binary to be used as both > primary and secondary process, I suggest looking at the symmetric_mp > example application in the examples/multi_process/ directory. > > Regards, > /Bruce > > > > > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > Please refer to http://www.aricent.com/legal/email_disclaimer.html > for important disclosures regarding this electronic communication. > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > > > > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > Please refer to http://www.aricent.com/legal/email_disclaimer.html > for important disclosures regarding this electronic communication. > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > > > > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > Please refer to http://www.aricent.com/legal/email_disclaimer.html > for important disclosures regarding this electronic communication. > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D Please refer to http://www.aricent.com/legal/email_disclaimer.html for important disclosures regarding this electronic communication. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D