1 files changed, 40 insertions, 3 deletions

diff --git a/Documentation/sysctl/net.txt b/Documentation/sysctl/net.txt
index 6f1c201319de..d69e14c9002c 100644
--- a/Documentation/sysctl/net.txt
+++ b/Documentation/sysctl/net.txt
@@ -26,7 +26,7 @@ Table : Subdirectories in /proc/sys/net
  ipv4      IP version 4        x25        X.25 protocol
  ipx       IPX                 token-ring IBM token ring
  bridge    Bridging            decnet     DEC net
- ipv6      IP version 6
+ ipv6      IP version 6        tipc       TIPC
 ..............................................................................
 
 1. /proc/sys/net/core - Network core options
@@ -50,6 +50,29 @@ The maximum number of packets that kernel can handle on a NAPI interrupt,
 it's a Per-CPU variable.
 Default: 64
 
+low_latency_read
+----------------
+Low latency busy poll timeout for socket reads. (needs CONFIG_NET_LL_RX_POLL)
+Approximate time in us to busy loop waiting for packets on the device queue.
+This sets the default value of the SO_LL socket option.
+Can be set or overridden per socket by setting socket option SO_LL, which is
+the preferred method of enabling.
+If you need to enable the feature globally via sysctl, a value of 50 is recommended.
+Will increase power usage.
+Default: 0 (off)
+
+low_latency_poll
+----------------
+Low latency busy poll timeout for poll and select. (needs CONFIG_NET_LL_RX_POLL)
+Approximate time in us to busy loop waiting for events.
+Recommended value depends on the number of sockets you poll on.
+For several sockets 50, for several hundreds 100.
+For more than that you probably want to use epoll.
+Note that only sockets with SO_LL set will be busy polled, so you want to either
+selectively set SO_LL on those sockets or set sysctl.net.low_latency_read globally.
+Will increase power usage.
+Default: 0 (off)
+
 rmem_default
 ------------
 
@@ -93,8 +116,7 @@ netdev_budget
 
 Maximum number of packets taken from all interfaces in one polling cycle (NAPI
 poll). In one polling cycle interfaces which are registered to polling are
-probed in a round-robin manner. The limit of packets in one such probe can be
-set per-device via sysfs class/net/<device>/weight .
+probed in a round-robin manner.
 
 netdev_max_backlog
 ------------------
@@ -201,3 +223,18 @@ IPX.
 The /proc/net/ipx_route  table  holds  a list of IPX routes. For each route it
 gives the  destination  network, the router node (or Directly) and the network
 address of the router (or Connected) for internal networks.
+
+6. TIPC
+-------------------------------------------------------
+
+The TIPC protocol now has a tunable for the receive memory, similar to the
+tcp_rmem - i.e. a vector of 3 INTEGERs: (min, default, max)
+
+    # cat /proc/sys/net/tipc/tipc_rmem
+    4252725 34021800        68043600
+    #
+
+The max value is set to CONN_OVERLOAD_LIMIT, and the default and min values
+are scaled (shifted) versions of that same value.  Note that the min value
+is not at this point in time used in any meaningful way, but the triplet is
+preserved in order to be consistent with things like tcp_rmem.