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

[Burakov, Anatoly]

Hi again David/Didier,

> Can I suggest to do an RTE_MAX between (internal_config.memory -
> total_mem) and (internal_config.memory * cpu_per_socket[socket_id] +
> rte_lcore_count() - 1) / rte_lcore_count() ? I don't think it's a good idea to go
> over the requested amount. Let the last core have a chance of reserving
> slightly less memory than other cores, but don't let it go over the limit. If
> specific memory constraints are required, let the user use --socket-mem
> instead.

Sorry for spamming, but now that I think of it, I don't believe this change makes much sense. If the user wants memory on specific sockets, there's already --socket-mem option. If the user doesn't care, there's -m option, which gives the user memory from whatever sockets it is available. With this change applied, DPDK will fail when run with -m switch under certain circumstances (e.g. cores from socket 0 present in the coremask but no memory left on socket 0), which is quite the opposite of a simple "give me n megs, I don't care where it comes from" option -m is providing.

Best regards,
Anatoly Burakov
DPDK SW Engineer

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