Re: [dpdk-dev] memory allocation requirements

[Olivier Matz <olivier.matz@6wind.com>]

Hi,

On 04/14/2016 05:39 PM, Sergio Gonzalez Monroy wrote:
>> Just to mention that some evolutions [1] are planned in mempool in
>> 16.07, allowing to populate a mempool with several chunks of memory,
>> and still ensuring that the objects are physically contiguous. It
>> completely removes the need to allocate a big virtually contiguous
>> memory zone (and also physically contiguous if not using
>> rte_mempool_create_xmem(), which is probably the case in most of
>> the applications).
>>
>> Knowing this, the code that remaps the hugepages to get the largest
>> possible physically contiguous zone probably becomes useless after
>> the mempool series. Changing it to only one mmap(file) in hugetlbfs
>> per NUMA socket would clearly simplify this part of EAL.
>>
> 
> Are you suggesting to make those changes after the mempool series
> has been applied but keeping the current memzone/malloc behavior?

I wonder if the default property of memzone/malloc which is to
allocate physically contiguous memory shouldn't be dropped. It could
remain optional, knowing that allocating a physically contiguous zone
larger than a page cannot be guaranteed.

But yes, I'm in favor of doing these changes in eal_memory.c, it would
drop a lot a complex code (all rtemap* stuff), and today I'm not seeing
any big issue of doing it... maybe we'll find one during the
discussion :)

Regards,
Olivier