Re: [dpdk-dev] [dpdk-techboard] DPDK ABI/API Stability

[David Marchand <david.marchand@redhat.com>]

On Mon, Apr 8, 2019 at 5:52 PM Burakov, Anatoly <anatoly.burakov@intel.com>
wrote:

However, there are two use cases that i can think of that are either
> hard or outright not possible without our multiprocess API's. The first
> one is dumping functionality. For example, dpdk_proc_info can display
> info from a currently-running or defunct process - list its
> memzones/mempools/etc. - basically, everything there is to know about
> the shared memory can be known that way. While this isn't a "real" use
> case, it is useful for debugging.
>

On the principle (there might be some corner cases I don't have an idea of)
attaching an existing process is something that can be done with PTRACE_*.
As for dumping post mortem, again, this could be done without dpdk assist.
The only thing that should come from dpdk is the knowledge of where and how
to dump the objects.



> More importantly, our multiprocess model provides resilience. In an
> event of a crash, the entire application is not brought down - instead,
> only the crashed process goes down. It's not /perfect/ resilience, of
> course, and there are caveats (memory leaking, locks, etc.), but you do
> get /some/ resilience that way - your process went down, you spin
> another secondary and you're back up and running again.
>

Never witnessed a recover, and yes I would suspect quite some funny
situations like locks, dirty memory etc...
Okay, thanks for the inputs.


-- 
David Marchand