Re: [RFC bpf-next 4/7] netdevice: introduce busy-poll setsockopt for AF_XDP

[Samudrala, Sridhar]

On 5/2/2019 1:39 AM, Magnus Karlsson wrote:
This patch introduces a new setsockopt that enables busy-poll for XDP
sockets. It is called XDP_BUSY_POLL_BATCH_SIZE and takes batch size as
an argument. A value between 1 and NAPI_WEIGHT (64) will turn it on, 0
will turn it off and any other value will return an error. There is
also a corresponding getsockopt implementation.

I think this socket option should also allow specifying a timeout value 
when using blocking poll() calls.
OR can we use SO_BUSY_POLL to specify this timeout value?


Signed-off-by: Magnus Karlsson <magnus.karls...@intel.com>
---
  include/uapi/linux/if_xdp.h | 1 +
  1 file changed, 1 insertion(+)

diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h
index caed8b1..be28a78 100644
--- a/include/uapi/linux/if_xdp.h
+++ b/include/uapi/linux/if_xdp.h
@@ -46,6 +46,7 @@ struct xdp_mmap_offsets {
  #define XDP_UMEM_FILL_RING            5
  #define XDP_UMEM_COMPLETION_RING      6
  #define XDP_STATISTICS                        7
+#define XDP_BUSY_POLL_BATCH_SIZE       8
  
  struct xdp_umem_reg {
        __u64 addr; /* Start of packet data area */