> -----Original Message----- > From: Intel-wired-lan [mailto:[email protected]] On > Behalf Of Magnus Karlsson > Sent: Tuesday, January 29, 2019 6:03 AM > To: Karlsson, Magnus <[email protected]>; Topel, Bjorn > <[email protected]>; [email protected] > Cc: [email protected] > Subject: [Intel-wired-lan] [PATCH net] i40e: fix potential RX buffer > starvation > for AF_XDP > > When the RX rings are created they are also populated with buffers so that > packets can be received. Usually these are kernel buffers, but for AF_XDP in > zero-copy mode, these are user-space buffers and in this case the > application might not have sent down any buffers to the driver at this point. > And if no buffers are allocated at ring creation time, no packets can be > received and no interupts will be generated so the napi poll function that > allocates buffers to the rings will never get executed. > > To rectify this, we kick the NAPI context of any queue with an attached > AF_XDP zero-copy socket in two places in the code. Once after an XDP > program has loaded and once after the umem is registered. > This take care of both cases: XDP program gets loaded first then AF_XDP > socket is created, and the reverse, AF_XDP socket is created first, then XDP > program is loaded. > > Fixes: 0a714186d3c0 ("i40e: add AF_XDP zero-copy Rx support") > Signed-off-by: Magnus Karlsson <[email protected]> > --- > drivers/net/ethernet/intel/i40e/i40e_main.c | 13 ++++++++++++- > drivers/net/ethernet/intel/i40e/i40e_xsk.c | 5 +++++ > 2 files changed, 17 insertions(+), 1 deletion(-)
Tested-by: Andrew Bowers <[email protected]>
