Thanks Bruce, I think your suggested example of multi_process answers my questions.
Regards -Prashant -----Original Message----- From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Prashant Upadhyaya Sent: Friday, November 22, 2013 7:10 PM To: Richardson, Bruce; dev at 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=auto, 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=auto is used ? Regards -Prashant -----Original Message----- From: Richardson, Bruce [mailto:bruce.richard...@intel.com] Sent: Friday, November 22, 2013 7:02 PM To: Prashant Upadhyaya; dev at dpdk.org Subject: RE: Query regarding multiple processes in DPDK Hi Prashant > === > The EAL also supports an auto-detection mode (set by EAL > --proc-type=auto flag), whereby an Intel(r) DPDK process is started as > a secondary instance if a primary instance is already running. > === > > 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 = 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=auto, 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 =============================================================================== Please refer to http://www.aricent.com/legal/email_disclaimer.html for important disclosures regarding this electronic communication. =============================================================================== =============================================================================== Please refer to http://www.aricent.com/legal/email_disclaimer.html for important disclosures regarding this electronic communication. ===============================================================================
