[dpdk-dev] [PATCH v2 13/41] eal: replace memseg with memseg lists

[Burakov, Anatoly]

On 24-Mar-18 12:23 PM, santosh wrote:
> 
> 
> On Saturday 24 March 2018 04:38 PM, Burakov, Anatoly wrote:
>> On 24-Mar-18 6:01 AM, santosh wrote:
>>> Hi Anatoly,
>>>
>>> Thanks for good work!.
>>> Few observations:
>>> # Noticed performance regression for thunderx platform for l3fwd application,
>>> drops by 3%. git bisect shows this changeset is offending commit.
>>> I'm still investigating reason for perf-dip..
>>> Would like to know - have you noticed any regression on x86 platform?
>>
>> I haven't noticed any regressions on x86. Would it by any chance be due to the fact that memory segments are now non-contiguous or are allocated from smaller page sizes first?
>>
>> I am in the process of preparing a v3, which moves some things around and is better at git bisect (and fixes all compile issues i am or was made aware of). Does performance regression also happen in legacy mode?
>>
> Test ran for legacy mode only and noticed performance regression.
> 
> Thanks.
> [..]
> 
> 

Legacy mode does not do IPC memory allocation, so that is out of the 
question. Does thunderx do any address translation or other memory 
lookups on fast path? That is the only thing that comes to mind that 
could affect performance once all allocations are complete.

-- 
Thanks,
Anatoly