* Will Deacon <will.deacon@xxxxxxx> wrote: > On Tue, Oct 24, 2017 at 11:31:04AM +0200, Ingo Molnar wrote: > > > > * Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> wrote: > > > > > From: Will Deacon <will.deacon@xxxxxxx> > > > > > > lockless_dereference is a nice idea, but its gained little traction in > > > kernel code since it's introduction three years ago. This is partly > > > > s/its/it > > s/it's/its > > Crikey, no idea what happened there! NP, just habitual drive-by typo fixing from me, would have fixed them silently when applying the patches, had it not been for the split-up suggestion :-) > > > because it's a pain to type, but also because using READ_ONCE instead > > > will work correctly on all architectures apart from Alpha, which is a > > > fully supported but somewhat niche architecture these days. > > > > > > This patch moves smp_read_barrier_depends() (a NOP on all architectures > > > other than Alpha) from lockless_dereference into READ_ONCE, converts > > > the few actual users over to READ_ONCE and then finally removes > > > lockless_dereference altogether. > > > > Nit: if we refer to smp_read_barrier_depends() with parentheses (which is the nice > > thing to do for function-alike symbols), then we should do the same with > > READ_ONCE() and lockless_dereference() as well. > > > > Also, could we please split this into three patches: > > > > #1: Add smp_read_barrier_depends() to READ_ONCE() > > #2: Convert all lockless_dereference() users to READ_ONCE() > > #3: Remove the now unused lockless_dereference() API > > > > to make it easier to analyze if bisected to, should any problems arise? > > Sure, I'll do that now. Thanks! Ingo
