Re: AF_XDP and dma
ratheesh kannoth <[email protected]>
| Newsgroups | org.kernel.vger.xdp-newbies |
|---|---|
| Message-ID | <CAGZFCEF5+WycmVFv9kdmRDc2s60mKa88VPLw_9+72W6DL37o1Q@mail.gmail.com> |
On Fri, Apr 9, 2021 at 4:36 PM Magnus Karlsson <[email protected]> wrote: > In XDP/AF_XDP mode, the NIC only uses a single 4K page (on x86-64) per > packet so it will be physically contiguous by definition. How ? if userspace allocates memory, it would be only contiguous in virtual address space. >Every single > page will be dma mapped separately and can reside anywhere. I agree. My concern is not on total memory. it is about each chunk. >There is > no scatter-gather in XDP/AF_XDP mode. i agree. i am not talking about Scatter gather (nr_frags or frag_list) > > > > > > > /Magnus