linux/include/net/inetpeer.h
Eric Dumazet 2c1409a0a2 inetpeer: Optimize inet_getid()
While investigating for network latencies, I found inet_getid() was a
contention point for some workloads, as inet_peer_idlock is shared
by all inet_getid() users regardless of peers.

One way to fix this is to make ip_id_count an atomic_t instead
of __u16, and use atomic_add_return().

In order to keep sizeof(struct inet_peer) = 64 on 64bit arches
tcp_ts_stamp is also converted to __u32 instead of "unsigned long".

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-13 20:46:58 -08:00

46 lines
1.2 KiB
C

/*
* INETPEER - A storage for permanent information about peers
*
* Authors: Andrey V. Savochkin <saw@msu.ru>
*/
#ifndef _NET_INETPEER_H
#define _NET_INETPEER_H
#include <linux/types.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/spinlock.h>
#include <asm/atomic.h>
struct inet_peer {
/* group together avl_left,avl_right,v4daddr to speedup lookups */
struct inet_peer *avl_left, *avl_right;
__be32 v4daddr; /* peer's address */
__u32 avl_height;
struct list_head unused;
__u32 dtime; /* the time of last use of not
* referenced entries */
atomic_t refcnt;
atomic_t rid; /* Frag reception counter */
atomic_t ip_id_count; /* IP ID for the next packet */
__u32 tcp_ts;
__u32 tcp_ts_stamp;
};
void inet_initpeers(void) __init;
/* can be called with or without local BH being disabled */
struct inet_peer *inet_getpeer(__be32 daddr, int create);
/* can be called from BH context or outside */
extern void inet_putpeer(struct inet_peer *p);
/* can be called with or without local BH being disabled */
static inline __u16 inet_getid(struct inet_peer *p, int more)
{
more++;
return atomic_add_return(more, &p->ip_id_count) - more;
}
#endif /* _NET_INETPEER_H */