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linux-next/net/tipc/node.h
Allan Stephens 672d99e19a tipc: Convert node object array to a hash table
Replaces the dynamically allocated array of pointers to the cluster's
node objects with a static hash table. Hash collisions are resolved
using chaining, with a typical hash chain having only a single node,
to avoid degrading performance during processing of incoming packets.
The conversion to a hash table reduces the memory requirements for
TIPC's node table to approximately the same size it had prior to
the previous commit.

In addition to the hash table itself, TIPC now also maintains a
linked list for the node objects, sorted by ascending network address.
This list allows TIPC to continue sending responses to user space
applications that request node and link information in sorted order.
The list also improves performance when name table update messages are
sent by making it easier to identify the nodes that must be notified.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-03-13 16:35:17 -04:00

135 lines
5.1 KiB
C

/*
* net/tipc/node.h: Include file for TIPC node management routines
*
* Copyright (c) 2000-2006, Ericsson AB
* Copyright (c) 2005, 2010-2011, 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.
*/
#ifndef _TIPC_NODE_H
#define _TIPC_NODE_H
#include "node_subscr.h"
#include "addr.h"
#include "net.h"
#include "bearer.h"
/**
* struct tipc_node - TIPC node structure
* @addr: network address of node
* @lock: spinlock governing access to structure
* @hash: links to adjacent nodes in unsorted hash chain
* @list: links to adjacent nodes in sorted list of cluster's nodes
* @nsub: list of "node down" subscriptions monitoring node
* @active_links: pointers to active links to node
* @links: pointers to all links to node
* @working_links: number of working links to node (both active and standby)
* @cleanup_required: non-zero if cleaning up after a prior loss of contact
* @link_cnt: number of links to node
* @permit_changeover: non-zero if node has redundant links to this system
* @bclink: broadcast-related info
* @supported: non-zero if node supports TIPC b'cast capability
* @acked: sequence # of last outbound b'cast message acknowledged by node
* @last_in: sequence # of last in-sequence b'cast message received from node
* @gap_after: sequence # of last message not requiring a NAK request
* @gap_to: sequence # of last message requiring a NAK request
* @nack_sync: counter that determines when NAK requests should be sent
* @deferred_head: oldest OOS b'cast message received from node
* @deferred_tail: newest OOS b'cast message received from node
* @defragm: list of partially reassembled b'cast message fragments from node
*/
struct tipc_node {
u32 addr;
spinlock_t lock;
struct hlist_node hash;
struct list_head list;
struct list_head nsub;
struct link *active_links[2];
struct link *links[MAX_BEARERS];
int link_cnt;
int working_links;
int cleanup_required;
int permit_changeover;
struct {
int supported;
u32 acked;
u32 last_in;
u32 gap_after;
u32 gap_to;
u32 nack_sync;
struct sk_buff *deferred_head;
struct sk_buff *deferred_tail;
struct sk_buff *defragm;
} bclink;
};
#define NODE_HTABLE_SIZE 512
extern struct list_head tipc_node_list;
/*
* A trivial power-of-two bitmask technique is used for speed, since this
* operation is done for every incoming TIPC packet. The number of hash table
* entries has been chosen so that no hash chain exceeds 8 nodes and will
* usually be much smaller (typically only a single node).
*/
static inline unsigned int tipc_hashfn(u32 addr)
{
return addr & (NODE_HTABLE_SIZE - 1);
}
extern u32 tipc_own_tag;
struct tipc_node *tipc_node_find(u32 addr);
struct tipc_node *tipc_node_create(u32 addr);
void tipc_node_delete(struct tipc_node *n_ptr);
struct tipc_node *tipc_node_attach_link(struct link *l_ptr);
void tipc_node_detach_link(struct tipc_node *n_ptr, struct link *l_ptr);
void tipc_node_link_down(struct tipc_node *n_ptr, struct link *l_ptr);
void tipc_node_link_up(struct tipc_node *n_ptr, struct link *l_ptr);
int tipc_node_has_active_links(struct tipc_node *n_ptr);
int tipc_node_has_redundant_links(struct tipc_node *n_ptr);
int tipc_node_is_up(struct tipc_node *n_ptr);
struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space);
struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space);
static inline void tipc_node_lock(struct tipc_node *n_ptr)
{
spin_lock_bh(&n_ptr->lock);
}
static inline void tipc_node_unlock(struct tipc_node *n_ptr)
{
spin_unlock_bh(&n_ptr->lock);
}
#endif