On Mon, Apr 27, 2020 at 11:10:54AM -0700, Sean Christopherson wrote: [...] > > It will "return (0xdeadull << 48)" as you proposed in abbed4fa94f6? :-) > > > > Frankly speaking I always preferred zero but that's just not true any more > > after above change. This also reminded me that maybe we should also return the > > same thing at [1] below. > > Ah, I was looking at this code: > > if (!slot || !slot->npages) > return 0; > > That means deletion returns different success values for "deletion was a > nop" and "deletion was successful". The nop path should probably return > (or fill in) "(unsigned long)(0xdeadull << 48)" as well. Yep. Since I touched the line here after all, I'll directly squash this small fix into this patch too when I repost. Thanks, [...] > > > > > > > } else { > > > > if (!slot || !slot->npages) > > > > - return 0; > > > > + return ERR_PTR_USR(0); > > > > [1] -- Peter Xu