Re: [dpdk-dev] [PATCH] eal: add function to check if primary proc alive

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, Jan 21, 2016 at 09:02:41AM +0000, Van Haaren, Harry wrote:
> > From: Qiu, Michael
> > Sent: Thursday, January 21, 2016 6:14 AM
> > To: Van Haaren, Harry <harry.van.haaren@intel.com>; david.marchand@6wind.com
> > Cc: dev@dpdk.org
> > Subject: Re: [dpdk-dev] [PATCH] eal: add function to check if primary proc alive
> > <snip>
> > As we could start up many primaries, how does your secondary process
> > work with them?
> 
> When a primary process initializes, the location of the config file is important. The default is /var/run/.rte_config
> 
> To run multiple primary processes, the --file-prefix= option is used to specific a custom location for the config file. Eg: --file-prefix=testing    /var/run/.testing_config
> 
> The rte_eal_check_primary_alive(const char*) function takes a char* parameter - this is the location of the config file that the secondary process will wait for. Setting it to the correct value will make this secondary process wait for the corresponding primary process.
> 
> Regards, -Harry

Since a given secondary process only works with a single primary process, I'm not
sure why the user should want or need to pass in this parameter. What's the use
case for a secondary process wanting to know about a different primary process?
The details of what the config file is should largely be hidden from the user
IMHO.

If you want to allow a secondary to query an arbitrary primary process can you
still allow a NULL string to query the default primary based on the passed in
file-prefix parameter (if any)?

/Bruce