On 12/26, Linus Torvalds wrote: > > [ Ugh, removed the crazy cc list with tons of old addresses ] thanks. > So the optimization may be valid I don't think so, see my initial reply. unlike wait_event(), __pollwait() + the head/tail checks in pipe_poll() doesn't have the necessary barriers (at least in theory) afaics. Between add_wait_queue()->list_add() and LOAD(head/tail). > (the config option definitely is > not), but I think it needs to be explained much better. > > I end up being very nervous about this code because we've had bugs in > this area, exactly because people optimize this code for the unixbench > pipe benchmark. Agreed! Oleg.
