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

["Qiu, Michael" <michael.qiu@intel.com>]

On 1/20/2016 9:26 PM, Harry van Haaren wrote:
> This patch adds a new function to the EAL API:
> int rte_eal_primary_proc_alive(const char *path);
>
> The function indicates if a primary process is alive right now.
> This functionality is implemented by testing for a write-
> lock on the config file, and the function tests for a lock.
>
> The use case for this functionality is that a secondary
> process can wait until a primary process starts by polling
> the function and waiting. When the primary is running, the
> secondary continues to poll to detect if the primary process
> has quit unexpectedly, the secondary process can detect this.
>
> The RTE_MAGIC number is written to the shared config by the
> primary process, this is the signal to the secondary process
> that the EAL is set up, and ready to be used. The function
> rte_eal_mcfg_complete() writes RTE_MAGIC. This has been
> delayed in the EAL init proceedure, as the PCI probing in
> the primary process can interfere with the secondary running.
>
> Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
> ---

one question:

As we could start up many primaries, how does your secondary process
work with them?

Thanks,
Michael