RE: [PATCH v10 01/20] dlb: add skeleton for DLB driver

From: Chen, Mike Ximing
Date: Thu Feb 18 2021 - 13:11:43 EST




> -----Original Message-----
> From: gregkh@xxxxxxxxxxxxxxxxxxx <gregkh@xxxxxxxxxxxxxxxxxxx>
> Sent: Thursday, February 18, 2021 2:53 AM
> To: Chen, Mike Ximing <mike.ximing.chen@xxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx; Linux Kernel Mailing List <linux-
> kernel@xxxxxxxxxxxxxxx>; davem@xxxxxxxxxxxxx; kuba@xxxxxxxxxx; arnd@xxxxxxxx;
> Williams, Dan J <dan.j.williams@xxxxxxxxx>; pierre-louis.bossart@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v10 01/20] dlb: add skeleton for DLB driver
>
> On Thu, Feb 18, 2021 at 07:34:31AM +0000, Chen, Mike Ximing wrote:
> >
> >
> > > -----Original Message-----
> > > From: Mike Ximing Chen <mike.ximing.chen@xxxxxxxxx>
> > > Sent: Wednesday, February 10, 2021 12:54 PM
> > > To: netdev@xxxxxxxxxxxxxxx
> > > Cc: davem@xxxxxxxxxxxxx; kuba@xxxxxxxxxx; arnd@xxxxxxxx;
> > > gregkh@xxxxxxxxxxxxxxxxxxx; Williams, Dan J <dan.j.williams@xxxxxxxxx>;
> pierre-
> > > louis.bossart@xxxxxxxxxxxxxxx; Gage Eads <gage.eads@xxxxxxxxx>
> > > Subject: [PATCH v10 01/20] dlb: add skeleton for DLB driver
> > >
> > > diff --git a/Documentation/misc-devices/dlb.rst b/Documentation/misc-
> > > devices/dlb.rst
> > > new file mode 100644
> > > index 000000000000..aa79be07ee49
> > > --- /dev/null
> > > +++ b/Documentation/misc-devices/dlb.rst
> > > @@ -0,0 +1,259 @@
> > > +.. SPDX-License-Identifier: GPL-2.0-only
> > > +
> > > +===========================================
> > > +Intel(R) Dynamic Load Balancer Overview
> > > +===========================================
> > > +
> > > +:Authors: Gage Eads and Mike Ximing Chen
> > > +
> > > +Contents
> > > +========
> > > +
> > > +- Introduction
> > > +- Scheduling
> > > +- Queue Entry
> > > +- Port
> > > +- Queue
> > > +- Credits
> > > +- Scheduling Domain
> > > +- Interrupts
> > > +- Power Management
> > > +- User Interface
> > > +- Reset
> > > +
> > > +Introduction
> > > +============
> > > +
> > > +The Intel(r) Dynamic Load Balancer (Intel(r) DLB) is a PCIe device that
> > > +provides load-balanced, prioritized scheduling of core-to-core communication.
> > > +
> > > +Intel DLB is an accelerator for the event-driven programming model of
> > > +DPDK's Event Device Library[2]. The library is used in packet processing
> > > +pipelines that arrange for multi-core scalability, dynamic load-balancing, and
> > > +variety of packet distribution and synchronization schemes.
> > > +
> > > +Intel DLB device consists of queues and arbiters that connect producer
> > > +cores and consumer cores. The device 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.
> > > +
> >
> > Hi Jakub/Dave,
> > This is a device driver for a HW core-to-core communication accelerator. It is
> submitted
> > to "linux-kernel" for a module under device/misc. Greg suggested (see below) that
> we
> > also sent it to you for any potential feedback in case there is any interaction with
> > networking initiatives. The device is used to handle the load balancing among CPU
> cores
> > after the packets are received and forwarded to CPU. We don't think it interferes
> > with networking operations, but would appreciate very much your
> review/comment on this.
>
> It's the middle of the merge window, getting maintainers to review new
> stuff until after 5.12-rc1 is out is going to be a very difficult thing
> to do.
>
> In the meantime, why don't you all help out and review submitted patches
> to the mailing lists for the subsystems you all are trying to get this
> patch into. I know maintainers would appreciate the help, right?
>
> thanks,
>
> greg k-h

Sure. I am a little new to the community and process, but will try to help.
Thanks
Mike