[PATCH v2 4/6] eal/memory: get rid of global VA space limits

[Burakov, Anatoly]

On 5/26/2026 6:02 PM, Bruce Richardson wrote:
> On Fri, Mar 13, 2026 at 04:06:35PM +0000, Anatoly Burakov wrote:
>> Currently, all VA space reservations take into account global memory limit.
>> The original intent was to limit memory allocations to however many NUMA
>> nodes the machine had taking into the account that socket ID's may be
>> discontiguous. Since we have had "socket count" API for while and it gives
>> us correct NUMA node count, taking discontiguousness into account, we can
>> relax the total limits and remove the restrictions, and let VA space usage
>> scale with NUMA nodes.
>>
>> The only place where we actually require a hard limit is in 32-bit code,
>> where we cannot allocate more than 2G of VA space.
>>
>> Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
> 
> Acked-by: Bruce Richardson <bruce.richardson at intel.com>
> 
> Asking AI about this patch flags an issue whereby the contigmem driver does
> not guarantee the number of buffers is >0, which can cause issues. However,
> that's better fixed in contigmem.
> 
> One additional comment inline below.
> 

<snip>

>> diff --git a/doc/guides/prog_guide/env_abstraction_layer.rst b/doc/guides/prog_guide/env_abstraction_layer.rst
>> index 04368a3950..63e0568afa 100644
>> --- a/doc/guides/prog_guide/env_abstraction_layer.rst
>> +++ b/doc/guides/prog_guide/env_abstraction_layer.rst
>> @@ -208,8 +208,6 @@ variables:
>>     can have (where "type" is defined as "page size + NUMA node" combination)
> 
> Is the RTE_MAX_MEMSEG_PER_TYPE value still necessary?

Yes, the "per list" values are gone, but "per type" values stay as they 
provide the defaults.

> 
>>   * ``RTE_MAX_MEM_MB_PER_TYPE`` controls how much megabytes of memory each
>>     memory type can address
>> -* ``RTE_MAX_MEM_MB`` places a global maximum on the amount of memory
>> -  DPDK can reserve
>>
> <snip>


-- 
Thanks,
Anatoly