Re: [dpdk-dev] [PATCH 0/2] Allow application set mempool handle

[Jerin Jacob <jerin.jacob@caviumnetworks.com>]

-----Original Message-----
> Date: Mon, 19 Jun 2017 17:22:46 +0530
> From: Hemant Agrawal <hemant.agrawal@nxp.com>
> To: Santosh Shukla <santosh.shukla@caviumnetworks.com>,
>  olivier.matz@6wind.com, dev@dpdk.org
> CC: jerin.jacob@caviumnetworks.com
> Subject: Re: [PATCH 0/2] Allow application set mempool handle
> User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101
>  Thunderbird/45.8.0
> 
> On 6/1/2017 1:35 PM, Santosh Shukla wrote:
> > Some platform can have two different NICs for example external PCI Intel
> > 40G card and Integrated NIC like vNIC/octeontx/dpaa2.
> > 
> > Both NICs like to use their preferred pool e.g. external PCI card/ vNIC's
> > preferred pool would be the ring based pool and octeontx/dpaa2 preferred would
> > be ext-mempools.
> > Right now, Framework doesn't support such case. Only one pool can be
> > used across two different NIC's. For that, user has to statically set
> > CONFIG_RTE_MEMPOOL_DEFAULT_OPS=<pool-name>.
> > 
> > So proposing two approaches:
> > Patch 1) Introducing eal option --pkt-mempool=<pool-name>
> > Patch 2) Introducing ethdev API called _get_preferred_pool(), where PMD driver
> > gets a chance to advertise their pool capability to the application. And based
> > on that hint- application creates pools for that driver.
> > 
> The idea is good. it will help the vendors with hw mempool support.
> 
> On a similar line, I also submitted a patch to check the existence of a
> mempool instance.
> http://dpdk.org/dev/patchwork/patch/15877/
> 
> Option 1) requires manual knowledge of underlying NIC and different commands
> for different machines.
> 
> Option 2) this will help more as it allows the application to take decision
> autonomously.
> 
> In addition to it, we can also extend the overall MEMPOOL_OPS support.
>  3)  currently we support defining only one "RTE_MBUF_DEFAULT_MEMPOOL_OPS"
>     this can be supported to publish a priority list of MEMPOOL_OPS in
> config. if one is not available, application can try the next one in
> priority list as supported by the platform.
> 
> 4) we can also try something, where the existing application can also be
> supported.
>         - default mempool is configured as alias. This is with empty ops.
>         - based on the mempool detections on the bus, the bus configure the
> mempool ops internally with the actual ones.

What if both HW are on PCIe bus(That the case for us)? Any scheme to fix
that?


> 
> 
> > Santosh Shukla (2):
> >   eal: Introducing option to set mempool handle
> >   ether/ethdev: Allow pmd to advertise preferred pool capability
> > 
> >  lib/librte_eal/bsdapp/eal/eal.c                 |  9 +++++++
> >  lib/librte_eal/bsdapp/eal/rte_eal_version.map   |  7 +++++
> >  lib/librte_eal/common/eal_common_options.c      |  3 +++
> >  lib/librte_eal/common/eal_internal_cfg.h        |  2 ++
> >  lib/librte_eal/common/eal_options.h             |  2 ++
> >  lib/librte_eal/common/include/rte_eal.h         |  9 +++++++
> >  lib/librte_eal/linuxapp/eal/eal.c               | 36 +++++++++++++++++++++++++
> >  lib/librte_eal/linuxapp/eal/rte_eal_version.map |  7 +++++
> >  lib/librte_ether/rte_ethdev.c                   | 16 +++++++++++
> >  lib/librte_ether/rte_ethdev.h                   | 21 +++++++++++++++
> >  lib/librte_ether/rte_ether_version.map          |  7 +++++
> >  lib/librte_mbuf/rte_mbuf.c                      |  8 ++++--
> >  12 files changed, 125 insertions(+), 2 deletions(-)
> > 
> 
>