[dpdk-dev] [PATCH 00/22] Add DLB2 PMD

[McDaniel, Timothy]

> -----Original Message-----
> From: Jerin Jacob <jerinjacobk at gmail.com>
> Sent: Tuesday, September 29, 2020 1:46 PM
> To: McDaniel, Timothy <timothy.mcdaniel at intel.com>; Thomas Monjalon
> <thomas at monjalon.net>; David Marchand <david.marchand at redhat.com>;
> Ma, Liang J <liang.j.ma at intel.com>
> Cc: dpdk-dev <dev at dpdk.org>; Carrillo, Erik G <Erik.G.Carrillo at intel.com>;
> Eads, Gage <gage.eads at intel.com>; Van Haaren, Harry
> <harry.van.haaren at intel.com>; Jerin Jacob <jerinj at marvell.com>
> Subject: Re: [dpdk-dev] [PATCH 00/22] Add DLB2 PMD
> 
> On Sat, Sep 12, 2020 at 2:00 AM Timothy McDaniel
> <timothy.mcdaniel at intel.com> wrote:
> >
> > The following patch series adds support for a new eventdev PMD. The DLB2
> > PMD adds support for the Intel Dynamic Load Balancer 2.0 (DLB2)
> > hardware.
> > The DLB2 is a PCIe device that provides load-balanced, prioritized
> > scheduling of core-to-core communication. The device consists of
> > queues and arbiters that connect producer and consumer cores, and
> > implements load-balanced queueing features including:
> > - Lock-free multi-producer/multi-consumer operation.
> > - Multiple priority levels for varying traffic types.
> > - 'Direct' traffic (i.e. multi-producer/single-consumer)
> > - Simple unordered load-balanced distribution.
> > - Atomic lock-free load balancing across multiple consumers.
> > - Queue element reordering feature allowing ordered load-balanced
> >   distribution.
> >
> > The DLB2 hardware supports both load balanced and directed ports and
> > queues. Unlike other eventdev devices already in the repo,  not all
> > DLB2 ports and queues are equally capable. In particular, directed
> > ports are limited to a single link, and must be connected to a
> > directed queue. Additionally, even though LDB ports may link multiple queues,
> > the number of queues that may be linked is limited by hardware.
> >
> > While reviewing the code, please be aware that this PMD has full
> > control over the DLB2 hardware. Intel will be extending the DLB2 PMD
> > in the future (not as part of this first series) with a mode that we
> > refer to as the bifurcated PMD. The bifurcated PMD communicates with a
> > kernel driver to configure the device, ports, and queues, and memory
> > maps device MMIO so datapath operations occur purely in user-space.
> > Note that the DLB2 hardware is a successor of the DLB hardware, and
> > as such is structured similarly, both in terms of code layout and
> > implementation.
> >
> > The framework to support both the PF PMD and bifurcated PMD exists in
> > this patchset, and is why the iface.[ch] layer is present.
> >
> > Depends-on: patch-77466 ("eventdev: add PCI probe named convenience
> function")
> > Depends-on: series-12160 ("Eventdev ABI changes")
> > Depends-on: patch-77460 ("eal: add umonitor umwait to x86 cpuflags")
> 
> Cc: Thomas and David
> 
> There is a duplicate for patch-77460 as
> https://patches.dpdk.org/patch/76554/ from different authors,
> and both are open comments to be closed.
> @McDaniel, Timothy and @Liang Ma , We need to have this eal patch on
> master before I merge this
> patch series in eventdev-next. Please check.
> 
> 

We have discussed this duplication with @Liang Ma, who split out just the
bit definitions into its own patch. DLB/DLB2 have been updated to use his new patch going forward,
but will duplicate it here until it is merged.