On 06/10, Oleg Nesterov wrote: > > On 06/10, Andrea Parri wrote: > > > > More simply/clean, as you said, maybe; one advantage of keeping > > the "raw" smp_read_barrier_depends() in get_trampoline_vaddr() is > > that we can avoid it when area is NULL; > > Do you really think it makes sense to optimize out read_barrier_depends here? > > It can only be NULL in handle_swbp(), and in this case we are going to do a > lot of work, and in particular install this xol vma,
Not to mention that alpha doesn't support uprobes, so this all is currently cosmetic. > > a similar solution is adopt- > > ed in kernel/task_work.c:task_work_cancel(). > > Heh ;) this code was written before we had lockless_dereference(). And I do > remember I thought that we need such a helper when read_barrier_depends() > was added. Plus this code still use ACCESS_ONCE for the same reason. I'll send a simple patch, it should not conflict with "Update spin_unlock_wait users" from Peter. Oleg.
