* Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > On Wed, Jul 4, 2018 at 3:38 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > > On Tue, Jul 03, 2018 at 10:30:40AM +0200, Ingo Molnar wrote: > >> > >> * Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > >> > >> > Hi Ingo, > >> > > >> > Here is an additional copy_to_iter_mcsafe() fix to address the crash > >> > reported by Ross. This now passes xfstests:generic/323 on my system. > >> > >> The lib/iov_iter fix would need an Acked-by from Al. > > > > I can live with that; I would really like to see some documentation on > > the copy_to_iter_mcsafe(), but that's a separate story. Incidentally, > > are there any expectations of other callers appearing, or is that > > (and copy_from_iter_flushcache()) YASingleConsumerAPI? > > The current cpu architectural detail preventing conversion of the > standard copy_to_iter() path to use the mcsafe flavor is that we can't > use REP MOV for fast copies and instead need to use a software loop so > that any exceptions are recoverable. When / if that is addressed, and > there is no performance difference between the two, it might make > sense to convert more users. > > The _flushcache flavor, however, will likely stay limited to a single > consumer for the persistent memory use case. Could you please add the API documentation Al asked for, and update the changlog with the acks and tested-by's that people gave, and send out a v2 series? Thanks! Ingo
