From: Van Haaren, Harry
Sent: Tuesday, February 23, 2016 2:10 PM
To: david.marchand@6wind.com
Cc: Tahhan, Maryam <redacted>; dev@dpdk.org; Van
Haaren, Harry [off-list ref]
Subject: [PATCH v4] eal: add function to check if primary proc alive

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 <redacted>

Acked-by: Maryam Tahhan <redacted>