linux/net/tipc/core.c
Jon Paul Maloy 6163a194e0 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 <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-14 15:19:47 -04:00

183 lines
4.8 KiB
C

/*
* net/tipc/core.c: TIPC module code
*
* Copyright (c) 2003-2006, 2013, Ericsson AB
* Copyright (c) 2005-2006, 2010-2013, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "core.h"
#include "ref.h"
#include "name_table.h"
#include "subscr.h"
#include "config.h"
#include "port.h"
#include <linux/module.h>
/* global variables used by multiple sub-systems within TIPC */
int tipc_random __read_mostly;
/* configurable TIPC parameters */
u32 tipc_own_addr __read_mostly;
int tipc_max_ports __read_mostly;
int tipc_net_id __read_mostly;
int sysctl_tipc_rmem[3] __read_mostly; /* min/default/max */
/**
* tipc_buf_acquire - creates a TIPC message buffer
* @size: message size (including TIPC header)
*
* Returns a new buffer with data pointers set to the specified size.
*
* NOTE: Headroom is reserved to allow prepending of a data link header.
* There may also be unrequested tailroom present at the buffer's end.
*/
struct sk_buff *tipc_buf_acquire(u32 size)
{
struct sk_buff *skb;
unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u;
skb = alloc_skb_fclone(buf_size, GFP_ATOMIC);
if (skb) {
skb_reserve(skb, BUF_HEADROOM);
skb_put(skb, size);
skb->next = NULL;
}
return skb;
}
/**
* tipc_core_stop - switch TIPC from SINGLE NODE to NOT RUNNING mode
*/
static void tipc_core_stop(void)
{
tipc_net_stop();
tipc_bearer_cleanup();
tipc_netlink_stop();
tipc_subscr_stop();
tipc_nametbl_stop();
tipc_ref_table_stop();
tipc_socket_stop();
tipc_unregister_sysctl();
}
/**
* tipc_core_start - switch TIPC from NOT RUNNING to SINGLE NODE mode
*/
static int tipc_core_start(void)
{
int err;
get_random_bytes(&tipc_random, sizeof(tipc_random));
err = tipc_ref_table_init(tipc_max_ports, tipc_random);
if (err)
goto out_reftbl;
err = tipc_nametbl_init();
if (err)
goto out_nametbl;
err = tipc_netlink_start();
if (err)
goto out_netlink;
err = tipc_socket_init();
if (err)
goto out_socket;
err = tipc_register_sysctl();
if (err)
goto out_sysctl;
err = tipc_subscr_start();
if (err)
goto out_subscr;
err = tipc_bearer_setup();
if (err)
goto out_bearer;
return 0;
out_bearer:
tipc_subscr_stop();
out_subscr:
tipc_unregister_sysctl();
out_sysctl:
tipc_socket_stop();
out_socket:
tipc_netlink_stop();
out_netlink:
tipc_nametbl_stop();
out_nametbl:
tipc_ref_table_stop();
out_reftbl:
return err;
}
static int __init tipc_init(void)
{
int res;
pr_info("Activated (version " TIPC_MOD_VER ")\n");
tipc_own_addr = 0;
tipc_max_ports = CONFIG_TIPC_PORTS;
tipc_net_id = 4711;
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] = TIPC_CONN_OVERLOAD_LIMIT;
res = tipc_core_start();
if (res)
pr_err("Unable to start in single node mode\n");
else
pr_info("Started in single node mode\n");
return res;
}
static void __exit tipc_exit(void)
{
tipc_core_stop();
pr_info("Deactivated\n");
}
module_init(tipc_init);
module_exit(tipc_exit);
MODULE_DESCRIPTION("TIPC: Transparent Inter Process Communication");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_VERSION(TIPC_MOD_VER);