On Wed, Jun 28, 2017 at 03:36:54AM +0100, Maciej W. Rozycki wrote: > On Wed, 28 Jun 2017, Leonid Yegoshin wrote: > > > The bigger problem is a prefetch overrun to device registers. AT use is just > > nuisance. > > That isn't however what the patch addresses, not at least according to > the description provided. > > How far beyond the data copied do we prefetch anyway, and can't we simply > waste a page's worth of space or so at the physical end of each RAM area > present in a given system? Or perhaps use it for something we know for > sure that won't ever be copied. Prefetching may also bring data which has just been flushed back into caches so until this is fixed properly it's not a good idea on non-coherent platforms. Ralf
