On Wed, May 24, 2023 at 02:39:50PM -0700, Sean Christopherson wrote: > On Wed, May 24, 2023, Peter Zijlstra wrote: > > On Wed, May 24, 2023 at 01:16:03PM -0700, Sean Christopherson wrote: > > > Of course, the only accesses outside of mmu_lock are reads, so on x86 that > > > "atomic" access is just a READ_ONCE() load, but that's not the case for all > > > architectures. > > > > This is true on *all* archs. atomic_set() and atomic_read() are no more > > and no less than WRITE_ONCE() / READ_ONCE(). > > Ah, I take it s390's handcoded assembly routines are just a paranoid equivalents > and not truly special? "l" and "st" do sound quite generic... Yep, compiler *should* generate the same with READ_ONCE/WRITE_ONCE.
