[dpdk-web] [PATCH] update Arm roadmap for 20.08

[Honnappa Nagarahalli]

Thanks Thomas for your comments.

> -----Original Message-----
> From: Thomas Monjalon <thomas at monjalon.net>
> Sent: Tuesday, June 9, 2020 3:08 AM
> To: Honnappa Nagarahalli <Honnappa.Nagarahalli at arm.com>
> Cc: web at dpdk.org; nd <nd at arm.com>
> Subject: Re: [PATCH] update Arm roadmap for 20.08
> 
> 09/06/2020 05:28, Honnappa Nagarahalli:
> > Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
> 
> Additional explanation:
> Was announced in the dpdk-dev mailing list:
> http://mails.dpdk.org/archives/dev/2020-June/169542.html
> 
> > +- Bit operations APIs for PMDs
> > +- rte_atomic API deprecation with-in DPDK
> 
> Deprecation is not a feature to coordinate in the roadmap I think.
Ok, no problem. I just wanted to make sure that the community is on-board in reviewing the patch and making decisions. I guess the proposal on the mailing list is enough for that?

> 
> > +- Use C11 atomic semantics in mbuf, eventdev, eal interrupts
> > +- CPU frequency calculation using generic counter for Arm platforms
> > +- LPM library integration with RCU library
> 
> I would word it in reverse order: isn't it the RCU lib which is integrated in LPM?
I guess it is more about which library was created first. I will reverse the order.

> 
> > +- Change IO barriers to align with other-multi-copy atomicity memory
> model for Armv8-a
> 
> I don't understand "other-multi-copy atomicity".
There were few references provided in the patch. They are at [1], [2] and [3]. But, I guess it is not clear what this work item means exactly. I can change it as follows:

"Change IO barriers to use 'DMB' instruction for Armv8-a"

The patch itself is trivial. But, it is a basic change affecting all the drivers for Arm platforms. So, I would like to call out everyone's attention.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=22ec71615d824f4f11d38d0e55a88d8956b7e45f
[2] https://www.youtube.com/watch?v=i6DayghhA8Q
[3] https://www.cl.cam.ac.uk/~pes20/armv8-mca/

>