linux/include/net/inet_frag.h
Jesper Dangaard Brouer cd39a7890a net: cacheline adjust struct netns_frags for better frag performance
This small cacheline adjustment of struct netns_frags improves
performance significantly for the fragmentation code.

Struct members 'lru_list' and 'mem' are both hot elements, and it
hurts performance, due to cacheline bouncing at every call point,
when they share a cacheline.  Also notice, how mem is placed
together with 'high_thresh' and 'low_thresh', as they are used in
the compare operations together.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-29 13:36:23 -05:00

79 lines
2.1 KiB
C

#ifndef __NET_FRAG_H__
#define __NET_FRAG_H__
struct netns_frags {
int nqueues;
struct list_head lru_list;
/* Its important for performance to keep lru_list and mem on
* separate cachelines
*/
atomic_t mem ____cacheline_aligned_in_smp;
/* sysctls */
int timeout;
int high_thresh;
int low_thresh;
};
struct inet_frag_queue {
struct hlist_node list;
struct netns_frags *net;
struct list_head lru_list; /* lru list member */
spinlock_t lock;
atomic_t refcnt;
struct timer_list timer; /* when will this queue expire? */
struct sk_buff *fragments; /* list of received fragments */
struct sk_buff *fragments_tail;
ktime_t stamp;
int len; /* total length of orig datagram */
int meat;
__u8 last_in; /* first/last segment arrived? */
#define INET_FRAG_COMPLETE 4
#define INET_FRAG_FIRST_IN 2
#define INET_FRAG_LAST_IN 1
u16 max_size;
};
#define INETFRAGS_HASHSZ 64
struct inet_frags {
struct hlist_head hash[INETFRAGS_HASHSZ];
rwlock_t lock;
u32 rnd;
int qsize;
int secret_interval;
struct timer_list secret_timer;
unsigned int (*hashfn)(struct inet_frag_queue *);
void (*constructor)(struct inet_frag_queue *q,
void *arg);
void (*destructor)(struct inet_frag_queue *);
void (*skb_free)(struct sk_buff *);
bool (*match)(struct inet_frag_queue *q, void *arg);
void (*frag_expire)(unsigned long data);
};
void inet_frags_init(struct inet_frags *);
void inet_frags_fini(struct inet_frags *);
void inet_frags_init_net(struct netns_frags *nf);
void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f);
void inet_frag_kill(struct inet_frag_queue *q, struct inet_frags *f);
void inet_frag_destroy(struct inet_frag_queue *q,
struct inet_frags *f, int *work);
int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f, bool force);
struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
struct inet_frags *f, void *key, unsigned int hash)
__releases(&f->lock);
static inline void inet_frag_put(struct inet_frag_queue *q, struct inet_frags *f)
{
if (atomic_dec_and_test(&q->refcnt))
inet_frag_destroy(q, f, NULL);
}
#endif