[Stratos-dev] Re: [PATCH 2/2] xen: privcmd: Add support for ioeventfd

On 09-10-23, 10:40, Alex Bennée wrote:

I thought generally sync points act as full barriers. Doing a bunch of grepping I think ends at:

static __always_inline bool __mutex_unlock_fast(struct mutex *lock) { unsigned long curr = (unsigned long)current;

      return atomic_long_try_cmpxchg_release(&lock->owner, &curr, 0UL);

}

so you should already have completed your writes by that point.

I am not sure if depending on such indirect mechanisms to implement barriers for you is a good idea.

The situation here probably requires explicit barriers to make sure it doesn't break in future ?