[dpdk-dev] [PATCH 6/6] app/crypto-perf: use single mempool

[De Lara Guarch, Pablo]

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Akhil Goyal
> Sent: Wednesday, August 30, 2017 9:31 AM
> To: De Lara Guarch, Pablo <pablo.de.lara.guarch at intel.com>; Doherty,
> Declan <declan.doherty at intel.com>; Trahe, Fiona
> <fiona.trahe at intel.com>; Jain, Deepak K <deepak.k.jain at intel.com>;
> Griffin, John <john.griffin at intel.com>;
> jerin.jacob at caviumnetworks.com; hemant.agrawal at nxp.com
> Cc: dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 6/6] app/crypto-perf: use single
> mempool
>
> Hi Pablo,
> On 8/18/2017 1:35 PM, Pablo de Lara wrote:
> > In order to improve memory utilization, a single mempool is created,
> > containing the crypto operation and mbufs (one if operation is
> > in-place, two if out-of-place).
> > This way, a single object is allocated and freed per operation,
> > reducing the amount of memory in cache, which improves scalability.
> >
> > Signed-off-by: Pablo de Lara <pablo.de.lara.guarch at intel.com>
> > ---
> >   app/test-crypto-perf/cperf_ops.c             |  96 ++++++--
> >   app/test-crypto-perf/cperf_ops.h             |   2 +-
> >   app/test-crypto-perf/cperf_test_latency.c    | 350 ++++++++++++-------
---
> ----
> >   app/test-crypto-perf/cperf_test_throughput.c | 347
> > ++++++++++++------
> --------
> >   app/test-crypto-perf/cperf_test_verify.c     | 356 ++++++++++++--------
---
> ----
> >   5 files changed, 553 insertions(+), 598 deletions(-)
> >
> NACK.
> This patch replaces rte_pktmbuf_pool_create with the
> rte_mempool_create for mbufs, which is not a preferred way to allocate
memory for pktmbuf.
>
> Any example/test application in DPDK should not be using this, as this
> kind of usages will  not be compatible for all dpdk drivers in general.
>
> This kind of usages of rte_mempool_create will not work for any
> devices using hw offloaded memory pools for pktmbuf.
> one such example is dpaa2.

Hi Akhil, 

Sorry for the delay on this reply and thanks for the review.

I think, since we are not getting the buffers from the NIC, but we are allocating
them ourselves, it is not strictly required to call rte_pktmbuf_pool_create.
In the end, we only need them for memory for the crypto PMDs and we are not touching
anything in them, so I think using calling rte_mempool_create should work ok.
Having a single mempool would be way more performant and would avoid the scalability
issues that we are having in this application now, and knowing that this application
was created to test crypto PMD performance, I think it is worth trying this out.

What is it exactly needed for dpaa2? Is the mempool handler?
Would it work for you if I create the mempool in a similar way as what
rte_pktmbuf_pool_create is doing? Calling rte_mempool_set_ops_byname?

Thanks!
Pablo


>
> -Akhil