Re: Another possible use for LKMM, or a subset (strengthening) thereof

[Paul E. McKenney]

On Tue, Oct 19, 2021 at 10:28:04AM +0800, Boqun Feng wrote:
> On Mon, Oct 18, 2021 at 05:07:29PM -0700, Paul E. McKenney wrote:
> > On Tue, Oct 19, 2021 at 07:56:35AM +0800, Boqun Feng wrote:
> > > Hi Paul,
> > > 
> > > On Mon, Oct 18, 2021 at 03:53:13PM -0700, Paul E. McKenney wrote:
> > > > On Thu, Oct 07, 2021 at 01:56:21PM -0700, Paul E. McKenney wrote:
> > > > > Hello!
> > > > > 
> > > > > On the perhaps unlikely chance that this is new news of interest...
> > > > > 
> > > > > I have finally prototyped the full "So You Want to Rust the Linux
> > > > > Kernel?" series (as in marked "under construction").
> > > > > 
> > > > > https://paulmck.livejournal.com/62436.html
> > > > 
> > > > And this blog series is now proclaimed to be feature complete.
> > > > 
> > > > Recommendations (both short- and long-term) may be found in the last post,
> > > > "TL;DR: Memory-Model Recommendations for Rusting the Linux Kernel",
> > > > at https://paulmck.livejournal.com/65341.html.
> > > 
> > > Thanks for putting this together! For the short-term recommendations, I
> > > think one practical goal would be having the equivalent (or stronger)
> > > litmus tests in Rust for the ones in tools/memory-model/litmus-tests.
> > > The translation of litmus tests may be trivial, but it at least ensure
> > > us that Rust can support the existing patterns widely used in Linux
> > > kernel. Of course, the Rust litmus tests don't have to be able to run
> > > with herd, we just need some code snippest to check our understanding of
> > > Rust memory model. ;-)
> > 
> > It would be very helpful for klitmus to be able to check Rust-code memory
> > ordering, now that you mention it!  This would be useful (for example)
> > to test the Rust wrappers on weakly ordered systems, such as ARM's.
> > 
> 
> Right.
> 
> > > Besides, it's interesting to how things react with each if one function
> > > in the litmus test is in Rust and the other is in C ;-) Maybe this is a
> > > long-term goal.
> > > 
> > > Thoughts?
> > 
> > These issues are quite important.  How do you feel that they should be
> > tracked?
> > 
> 
> Yep, it's already in my list. I created a small repo to track all issues
> I know about LKMM for Rust:
> 
> 	https://github.com/fbq/lkmm-for-rust
> 
> It's still under construction, but I put the litmus test thing in that
> list.

Very good, thank you!

							Thanx, Paul