On Fri, Aug 02, 2024 at 08:24:49AM -0600, Keith Busch wrote: > On Thu, Aug 01, 2024 at 11:33:44AM -0600, Alex Williamson wrote: > > On Thu, 1 Aug 2024 14:13:55 -0300 > > Jason Gunthorpe <jgg@xxxxxxxx> wrote: > > > > > On Thu, Aug 01, 2024 at 10:52:18AM -0600, Alex Williamson wrote: > > > > > > We'd populate these new regions only for BARs that support prefetch and > > > > mmap > > > > > > That's not the point, prefetch has nothing to do with write combining. > > > > I was following the original proposal in this thread that added a > > prefetch flag to REGION_INFO and allowed enabling WC only for > > IORESOURCE_PREFETCH. > > Which itself follows the existing pattern from > pci_create_resource_files(), which creates a write combine > resource<X>_wc file only when IORESOURCE_PREFETCH is set. But yeah, > prefetch isn't necessary for wc, but it seems to indicate it's safe. Yes, I know, that code isn't right either... It seems to be the root of this odd "prefetch and WC are related" idea. Jason
