Re: [PATCH v4 3/4] locking/qspinlock: Add ARCH_USE_QUEUED_SPINLOCKS_XCHG32

Peter Zijlstra
2021-03-29T19:12:04Z

On Mon, Mar 29, 2021 at 01:16:53PM +0200, Peter Zijlstra wrote:
> Anyway, an additional 'funny' is that I suspect you cannot prove fwd
> progress of the entire primitive with any of this on. But who cares
> about details anyway.. :/

What's the architectural guarantee on LL/SC progress for RISC-V ? And
what if you double loop it like cmpxchg() ?