On 6/21/24 19:48, Mina Almasry wrote:
On Mon, Jun 17, 2024 at 7:17 AM Pavel Begunkov asml.silence@gmail.com wrote:
...
static inline unsigned long netmem_to_pfn(netmem_ref netmem) {
if (netmem_is_net_iov(netmem))return 0;IIRC 0 is a valid pfn. Not much of a concern since it's used only for tracing, but might make sense to pass some invalid pfn if there is one
AFAIU all non-negative pfns are technically valid pfns if the machine is big enough.
I could have this function return long long instead of unsigned long so I can return a negative number for errors, and then cast to unsigned long when I figure out it's actually a pfn. Seemed like such a hassle especially since the call site is just tracing that I figured it's not that worth it.
Yeah, sounds like an overkill for tracing
return page_to_pfn(netmem_to_page(netmem));...
static inline netmem_ref netmem_compound_head(netmem_ref netmem) {
/* niov are never compounded */if (netmem_is_net_iov(netmem))return netmem;return page_to_netmem(compound_head(netmem_to_page(netmem)));+static inline void *netmem_address(netmem_ref netmem)
I don't think it's used anywhere, do I miss it?
Ah, It's used by the GVE devmem implementation: https://github.com/mina/linux/commit/da89baa81873d457cbf7b49ee6b4f0d66855b20...
I could leave it out of this patch, then add it with the follow up GVE devmem implementation, but I figured almost for sure drivers are going to need this eventually, and it's small, so just put it here.
Either way is fine by me, checking the function is not leftovers