On Thu, Oct 22, 2020 at 02:16:50PM -0700, Davidlohr Bueso wrote: > Considering both end_dir_add() and d_alloc_parallel(), the > dir->i_dir_seq wants acquire/release semantics, therefore > micro-optimize for ll/sc archs and use finer grained barriers > to provide (load)-ACQUIRE ordering (L->S + L->L). This comes > at no additional cost for most of x86, as sane tso models will > have a nop for smp_rmb/smp_acquire__after_ctrl_dep. > > Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx> > --- > Alternatively I guess we could just use cmpxchg_acquire(). Please us cmpxchg_acquire() so that people who have no clue what the hell smp_acquire__after_ctrl_dep() means or does have some hope of understanding of what objects the ordering semantics in the function actually apply to.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
