On Mon, 12 Aug 2024 20:10:39 +0100 Pavel Begunkov wrote: > > 1. Drivers need to be able to say "I support unreadable netmem". > > Failure to report unreadable netmem support should cause the netlink > > API to fail when the user tries to bind dmabuf/io uring memory. > > > > 2. Drivers need to be able to say "I want a header pool (with readable > > netmem)" or "I want a data pool (potentially with unreadable netmem)". > > > > Pavel is suggesting implementing both of these in 2 different flags. > > > > Jakub is suggesting implementing both with 1 flag which says "I can > > support unreadable netmem for this pool" , and guarding against #1 > > with a refcount check to detect if a dmabuf pool should have been > > created but wasn't. > > That would be iffy IIUC, but I think Jakub just explicitly said > that the refcount trick was just for debugging purposes and not > for gauging errors like "providers are not supported by the driver". > > "Yup, the refcount (now: check of the page pool list) was meant > as a WARN_ONCE() to catch bad drivers." Sorry, insufficient caffeine level in the morning. We can't WARN_ONCE(), indeed.
