RE: [RFC PATCH v12 01/17] dlb: add skeleton for DLB driver

-----Original Message-----
From: Andrew Lunn <andrew@lunn.ch>
Sent: Wednesday, December 22, 2021 4:27 PM
To: Chen, Mike Ximing <redacted>
Cc: linux-kernel@vger.kernel.org; arnd@arndb.de; gregkh@linuxfoundation.org; Williams, Dan J
[off-list ref]; pierre-louis.bossart@linux.intel.com; netdev@vger.kernel.org;
davem@davemloft.net; kuba@kernel.org
Subject: Re: [RFC PATCH v12 01/17] dlb: add skeleton for DLB driver

quoted

quoted

pointing to skbufs? How are the lifetimes of skbufs managed? How do
you get skbufs out of the NIC? Are you using XDP?

This is not a network accelerator in the sense that it does not have
direct access to the network sockets/ports. We do not use XDP.

So not using XDP is a problem. I looked at previous versions of this patch, and it is all DPDK. But DPDK is
not in mainline, XDP is. In order for this to be merged into mainline you need a mainline user of it.

Maybe you should abandon mainline, and just get this driver merged into the DPDK fork of Linux?

Hi Andrew,

I am not sure why not using XDP is a problem. As mentioned earlier, the
DLB driver is not a part of network stack.  

DPDK is one of applications that can make a good use of DLB, but is not the
only one. We have applications that access DLB directly via the kernel driver API
without using DPDK. Even in a DPDK application, the only part that involves
DLB is the eventdev poll mod driver module, in which we can replace a
traditional software base queue manager with DLB. The network access and
receiving/transmitting data from/to NIC is, on the other hand, handled by
the ethdev in DPDK. The eventdev (and DLB) distributes packet processing
over multiple worker cores.

Thanks
Mike