[dpdk-dev] [PATCH RFC] eal: change default per socket memory allocation

[Burakov, Anatoly]

Hi David,

> Actually, if we don't care where memory is allocated, we can at least try to have the more common setup work properly (i.e. spread memory allocations based on used cores).
> I can see no usual setup where you want to use cores on a socket while having all memory on another socket but still expect performance to be good.
> 
> So here is another approach for Didier's patch.
> We can try to spread memory on numa sockets, if this fails, then we default to previous behavior but leave a trace with a warning log "Could not spread memory on numa sockets".
> 
> What do you think about this ?

Sounds like an overcomplication to me. There could be cases where performance doesn't matter, for example the -m switch could be used to run various tests (unit tests, functional tests etc.). For anything performance-related, the recommended option is to use --socket-mem, especially if you have NICs on specific sockets. Presumably, when you're setting up a coremask, you already know which sockets your cores are on, so I don't see a problem with specifying which sockets you want memory from.

Best regards,
Anatoly Burakov
DPDK SW Engineer