From: Sridhar Samudrala Date: Wed, 28 Oct 2020 01:15:22 +0000 (-0700) Subject: socket.7: Document SO_INCOMING_NAPI_ID X-Git-Tag: man-pages-5.09~25 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e8500ecc786f5ee5854d4aa810dcf5124e8ed23f;p=thirdparty%2Fman-pages.git socket.7: Document SO_INCOMING_NAPI_ID Signed-off-by: Sridhar Samudrala Signed-off-by: Michael Kerrisk --- diff --git a/man7/socket.7 b/man7/socket.7 index 850d3162fb..1f38273e9f 100644 --- a/man7/socket.7 +++ b/man7/socket.7 @@ -519,6 +519,18 @@ This provides optimal NUMA behavior and keeps CPU caches hot. .\" SO_REUSEPORT logic, selecting the socket to receive the packet, ignores .\" SO_INCOMING_CPU setting. .TP +.BR SO_INCOMING_NAPI_ID " (gettable since Linux 4.12)" +.\" getsockopt 6d4339028b350efbf87c61e6d9e113e5373545c9 +Returns a system level unique ID called NAPI ID that is associated with a RX +queue on which the last packet associated with that socket is received. +.IP +This can be used by an application to split the incoming flows among worker +threads based on the RX queue on which the packets associated with the flows +are received. It allows each worker thread to be associated with a NIC HW +receive queue and service all the connection requests received on that RX +queue. This mapping between a app thread and a HW NIC queue streamlines the +flow of data from the NIC to the application. +.TP .B SO_KEEPALIVE Enable sending of keep-alive messages on connection-oriented sockets. Expects an integer boolean flag.