Re: [PATCH v3] net/ixgbe: add proper memory barriers for some Rx functions

[Thomas Monjalon <thomas@monjalon.net>]

12/06/2023 13:58, zhoumin:
> On Mon, June 12, 2023 at 6:26PM, Thomas Monjalon wrote:
> > 15/05/2023 04:10, Zhang, Qi Z:
> >> From: Ruifeng Wang <Ruifeng.Wang@arm.com>
> >>> From: Min Zhou <zhoumin@loongson.cn>
> >>>> ---
> >>>> v3:
> >>>> - Use rte_smp_rmb() as the proper memory barrier instead of rte_rmb()
> >>>> ---
> >>>> v2:
> >>>> - Make the calling of rte_rmb() for all platforms
> >>>> ---
> > [...]
> >>> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> >> Applied to dpdk-next-net-intel.
> >>
> >> Thanks
> >> Qi
> >>
> > Why ignoring checkpatch?
> > It is saying:
> > "
> > Warning in drivers/net/ixgbe/ixgbe_rxtx.c:
> > Using rte_smp_[r/w]mb
> > "
> 
> 
> I'm sorry. Should we never use rte_smp_[r/w]mb in the driver's code?

No we should avoid.
It has been decided to slowly replace such barriers.
By the way, I think it is not enough documented.
You can find an explanation in doc/guides/rel_notes/deprecation.rst

I think we should also add some notes to
lib/eal/include/generic/rte_atomic.h
Tyler, Honnappa, Ruifeng, Konstantin, what do you think?