From 6163a194e02ab6cab2758b277a0ae082378dd4e6 Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Wed, 14 May 2014 05:39:08 -0400 Subject: [PATCH] tipc: decrease connection flow control window Memory overhead when allocating big buffers for data transfer may be quite significant. E.g., truesize of a 64 KB buffer turns out to be 132 KB, 2 x the requested size. This invalidates the "worst case" calculation we have been using to determine the default socket receive buffer limit, which is based on the assumption that 1024x64KB = 67MB buffers may be queued up on a socket. Since TIPC connections cannot survive hitting the buffer limit, we have to compensate for this overhead. We do that in this commit by dividing the fix connection flow control window from 1024 (2*512) messages to 512 (2*256). Since older version nodes send out acks at 512 message intervals, compatibility with such nodes is guaranteed, although performance may be non-optimal in such cases. Signed-off-by: Jon Maloy Reviewed-by: Ying Xue Signed-off-by: David S. Miller --- net/tipc/core.c | 7 ++++--- net/tipc/port.h | 9 +++++---- net/tipc/socket.c | 4 ++-- 3 files changed, 11 insertions(+), 9 deletions(-) diff --git a/net/tipc/core.c b/net/tipc/core.c index 57f8ae9aa466..676d18015dd8 100644 --- a/net/tipc/core.c +++ b/net/tipc/core.c @@ -154,10 +154,11 @@ static int __init tipc_init(void) tipc_max_ports = CONFIG_TIPC_PORTS; tipc_net_id = 4711; - sysctl_tipc_rmem[0] = CONN_OVERLOAD_LIMIT >> 4 << TIPC_LOW_IMPORTANCE; - sysctl_tipc_rmem[1] = CONN_OVERLOAD_LIMIT >> 4 << + sysctl_tipc_rmem[0] = TIPC_CONN_OVERLOAD_LIMIT >> 4 << + TIPC_LOW_IMPORTANCE; + sysctl_tipc_rmem[1] = TIPC_CONN_OVERLOAD_LIMIT >> 4 << TIPC_CRITICAL_IMPORTANCE; - sysctl_tipc_rmem[2] = CONN_OVERLOAD_LIMIT; + sysctl_tipc_rmem[2] = TIPC_CONN_OVERLOAD_LIMIT; res = tipc_core_start(); if (res) diff --git a/net/tipc/port.h b/net/tipc/port.h index a00397393bd1..5dfd165df1d7 100644 --- a/net/tipc/port.h +++ b/net/tipc/port.h @@ -42,9 +42,10 @@ #include "msg.h" #include "node_subscr.h" -#define TIPC_FLOW_CONTROL_WIN 512 -#define CONN_OVERLOAD_LIMIT ((TIPC_FLOW_CONTROL_WIN * 2 + 1) * \ - SKB_TRUESIZE(TIPC_MAX_USER_MSG_SIZE)) +#define TIPC_CONNACK_INTV 256 +#define TIPC_FLOWCTRL_WIN (TIPC_CONNACK_INTV * 2) +#define TIPC_CONN_OVERLOAD_LIMIT ((TIPC_FLOWCTRL_WIN * 2 + 1) * \ + SKB_TRUESIZE(TIPC_MAX_USER_MSG_SIZE)) /** * struct tipc_port - TIPC port structure @@ -187,7 +188,7 @@ static inline void tipc_port_unlock(struct tipc_port *p_ptr) static inline int tipc_port_congested(struct tipc_port *p_ptr) { - return (p_ptr->sent - p_ptr->acked) >= (TIPC_FLOW_CONTROL_WIN * 2); + return ((p_ptr->sent - p_ptr->acked) >= TIPC_FLOWCTRL_WIN); } diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 3f9912f87d0d..8685daf060f9 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1101,7 +1101,7 @@ restart: /* Consume received message (optional) */ if (likely(!(flags & MSG_PEEK))) { if ((sock->state != SS_READY) && - (++port->conn_unacked >= TIPC_FLOW_CONTROL_WIN)) + (++port->conn_unacked >= TIPC_CONNACK_INTV)) tipc_acknowledge(port->ref, port->conn_unacked); advance_rx_queue(sk); } @@ -1210,7 +1210,7 @@ restart: /* Consume received message (optional) */ if (likely(!(flags & MSG_PEEK))) { - if (unlikely(++port->conn_unacked >= TIPC_FLOW_CONTROL_WIN)) + if (unlikely(++port->conn_unacked >= TIPC_CONNACK_INTV)) tipc_acknowledge(port->ref, port->conn_unacked); advance_rx_queue(sk); } -- 2.20.1