[dpdk-dev] [PATCH v2] mempool: replace c memcpy code semantics with optimized rte_memcpy

Olivier Matz olivier.matz at 6wind.com
Fri Jun 24 18:04:37 CEST 2016



On 06/17/2016 12:40 PM, Olivier Matz wrote:
> Hi Jerin,
> 
> On 06/03/2016 09:02 AM, Jerin Jacob wrote:
>> On Thu, Jun 02, 2016 at 11:16:16PM +0200, Olivier MATZ wrote:
>> Hi Olivier,
>>
>>> This is probably more a measure of the pure CPU cost of the mempool
>>> function, without considering the memory cache aspect. So, of course,
>>> a real use-case test should be done to confirm or not that it increases
>>> the performance. I'll manage to do a test and let you know the result.
>>
>> OK
>>
>> IMO, put rte_memcpy makes sense(this patch) as their no behavior change.
>> However, if get rte_memcpy with behavioral changes makes sense some platform
>> then we can enable it on conditional basics(I am OK with that)
>>
>>>
>>> By the way, not all drivers are allocating or freeing the mbufs by
>>> bulk, so this modification would only affect these ones. What driver
>>> are you using for your test?
>>
>> I have tested with ThunderX nicvf pmd(uses the bulk mode).
>> Recently sent out driver in ml for review
> 
> Just to let you know I do not forget this. I still need to
> find some time to do a performance test.


Quoting from the other thread [1] too to save this in patchwork:
[1] http://dpdk.org/ml/archives/dev/2016-June/042701.html


> On 06/24/2016 05:56 PM, Hunt, David wrote:
>> Hi Jerin,
>>
>> I just ran a couple of tests on this patch on the latest master head on
>> a couple of machines. An older quad socket E5-4650 and a quad socket
>> E5-2699 v3
>>
>> E5-4650:
>> I'm seeing a gain of 2% for un-cached tests and a gain of 9% on the
>> cached tests.
>>
>> E5-2699 v3:
>> I'm seeing a loss of 0.1% for un-cached tests and a gain of 11% on the
>> cached tests.
>>
>> This is purely the autotest comparison, I don't have traffic generator
>> results. But based on the above, I don't think there are any performance
>> issues with the patch.
>>
> 
> Thanks for doing the test on your side. I think it's probably enough
> to integrate Jerin's patch .
> 
> About using a rte_memcpy() in the mempool_get(), I don't think I'll have
> the time to do a more exhaustive test before the 16.07, so I'll come
> back with it later.
> 
> I'm sending an ack on the v2 thread.


Acked-by: Olivier Matz <olivier.matz at 6wind.com>


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