linux-stable/include/net/act_api.h
Eric Dumazet 1c0d32fde5 net_sched: gen_estimator: complete rewrite of rate estimators
1) Old code was hard to maintain, due to complex lock chains.
   (We probably will be able to remove some kfree_rcu() in callers)

2) Using a single timer to update all estimators does not scale.

3) Code was buggy on 32bit kernel (WRITE_ONCE() on 64bit quantity
   is not supposed to work well)

In this rewrite :

- I removed the RB tree that had to be scanned in
  gen_estimator_active(). qdisc dumps should be much faster.

- Each estimator has its own timer.

- Estimations are maintained in net_rate_estimator structure,
  instead of dirtying the qdisc. Minor, but part of the simplification.

- Reading the estimator uses RCU and a seqcount to provide proper
  support for 32bit kernels.

- We reduce memory need when estimators are not used, since
  we store a pointer, instead of the bytes/packets counters.

- xt_rateest_mt() no longer has to grab a spinlock.
  (In the future, xt_rateest_tg() could be switched to per cpu counters)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-05 15:21:59 -05:00

206 lines
6 KiB
C

#ifndef __NET_ACT_API_H
#define __NET_ACT_API_H
/*
* Public action API for classifiers/qdiscs
*/
#include <net/sch_generic.h>
#include <net/pkt_sched.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
struct tcf_hashinfo {
struct hlist_head *htab;
unsigned int hmask;
spinlock_t lock;
u32 index;
};
struct tc_action_ops;
struct tc_action {
const struct tc_action_ops *ops;
__u32 type; /* for backward compat(TCA_OLD_COMPAT) */
__u32 order;
struct list_head list;
struct tcf_hashinfo *hinfo;
struct hlist_node tcfa_head;
u32 tcfa_index;
int tcfa_refcnt;
int tcfa_bindcnt;
u32 tcfa_capab;
int tcfa_action;
struct tcf_t tcfa_tm;
struct gnet_stats_basic_packed tcfa_bstats;
struct gnet_stats_queue tcfa_qstats;
struct net_rate_estimator __rcu *tcfa_rate_est;
spinlock_t tcfa_lock;
struct rcu_head tcfa_rcu;
struct gnet_stats_basic_cpu __percpu *cpu_bstats;
struct gnet_stats_queue __percpu *cpu_qstats;
};
#define tcf_head common.tcfa_head
#define tcf_index common.tcfa_index
#define tcf_refcnt common.tcfa_refcnt
#define tcf_bindcnt common.tcfa_bindcnt
#define tcf_capab common.tcfa_capab
#define tcf_action common.tcfa_action
#define tcf_tm common.tcfa_tm
#define tcf_bstats common.tcfa_bstats
#define tcf_qstats common.tcfa_qstats
#define tcf_rate_est common.tcfa_rate_est
#define tcf_lock common.tcfa_lock
#define tcf_rcu common.tcfa_rcu
static inline unsigned int tcf_hash(u32 index, unsigned int hmask)
{
return index & hmask;
}
static inline int tcf_hashinfo_init(struct tcf_hashinfo *hf, unsigned int mask)
{
int i;
spin_lock_init(&hf->lock);
hf->index = 0;
hf->hmask = mask;
hf->htab = kzalloc((mask + 1) * sizeof(struct hlist_head),
GFP_KERNEL);
if (!hf->htab)
return -ENOMEM;
for (i = 0; i < mask + 1; i++)
INIT_HLIST_HEAD(&hf->htab[i]);
return 0;
}
/* Update lastuse only if needed, to avoid dirtying a cache line.
* We use a temp variable to avoid fetching jiffies twice.
*/
static inline void tcf_lastuse_update(struct tcf_t *tm)
{
unsigned long now = jiffies;
if (tm->lastuse != now)
tm->lastuse = now;
if (unlikely(!tm->firstuse))
tm->firstuse = now;
}
static inline void tcf_tm_dump(struct tcf_t *dtm, const struct tcf_t *stm)
{
dtm->install = jiffies_to_clock_t(jiffies - stm->install);
dtm->lastuse = jiffies_to_clock_t(jiffies - stm->lastuse);
dtm->firstuse = jiffies_to_clock_t(jiffies - stm->firstuse);
dtm->expires = jiffies_to_clock_t(stm->expires);
}
#ifdef CONFIG_NET_CLS_ACT
#define ACT_P_CREATED 1
#define ACT_P_DELETED 1
struct tc_action_ops {
struct list_head head;
char kind[IFNAMSIZ];
__u32 type; /* TBD to match kind */
size_t size;
struct module *owner;
int (*act)(struct sk_buff *, const struct tc_action *,
struct tcf_result *);
int (*dump)(struct sk_buff *, struct tc_action *, int, int);
void (*cleanup)(struct tc_action *, int bind);
int (*lookup)(struct net *, struct tc_action **, u32);
int (*init)(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **act, int ovr,
int bind);
int (*walk)(struct net *, struct sk_buff *,
struct netlink_callback *, int, const struct tc_action_ops *);
void (*stats_update)(struct tc_action *, u64, u32, u64);
int (*get_dev)(const struct tc_action *a, struct net *net,
struct net_device **mirred_dev);
};
struct tc_action_net {
struct tcf_hashinfo *hinfo;
const struct tc_action_ops *ops;
};
static inline
int tc_action_net_init(struct tc_action_net *tn,
const struct tc_action_ops *ops, unsigned int mask)
{
int err = 0;
tn->hinfo = kmalloc(sizeof(*tn->hinfo), GFP_KERNEL);
if (!tn->hinfo)
return -ENOMEM;
tn->ops = ops;
err = tcf_hashinfo_init(tn->hinfo, mask);
if (err)
kfree(tn->hinfo);
return err;
}
void tcf_hashinfo_destroy(const struct tc_action_ops *ops,
struct tcf_hashinfo *hinfo);
static inline void tc_action_net_exit(struct tc_action_net *tn)
{
tcf_hashinfo_destroy(tn->ops, tn->hinfo);
kfree(tn->hinfo);
}
int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
struct netlink_callback *cb, int type,
const struct tc_action_ops *ops);
int tcf_hash_search(struct tc_action_net *tn, struct tc_action **a, u32 index);
u32 tcf_hash_new_index(struct tc_action_net *tn);
bool tcf_hash_check(struct tc_action_net *tn, u32 index, struct tc_action **a,
int bind);
int tcf_hash_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
struct tc_action **a, const struct tc_action_ops *ops, int bind,
bool cpustats);
void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est);
void tcf_hash_insert(struct tc_action_net *tn, struct tc_action *a);
int __tcf_hash_release(struct tc_action *a, bool bind, bool strict);
static inline int tcf_hash_release(struct tc_action *a, bool bind)
{
return __tcf_hash_release(a, bind, false);
}
int tcf_register_action(struct tc_action_ops *a, struct pernet_operations *ops);
int tcf_unregister_action(struct tc_action_ops *a,
struct pernet_operations *ops);
int tcf_action_destroy(struct list_head *actions, int bind);
int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
int nr_actions, struct tcf_result *res);
int tcf_action_init(struct net *net, struct nlattr *nla,
struct nlattr *est, char *n, int ovr,
int bind, struct list_head *);
struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
struct nlattr *est, char *n, int ovr,
int bind);
int tcf_action_dump(struct sk_buff *skb, struct list_head *, int, int);
int tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int, int);
int tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int, int);
int tcf_action_copy_stats(struct sk_buff *, struct tc_action *, int);
#endif /* CONFIG_NET_CLS_ACT */
static inline void tcf_action_stats_update(struct tc_action *a, u64 bytes,
u64 packets, u64 lastuse)
{
#ifdef CONFIG_NET_CLS_ACT
if (!a->ops->stats_update)
return;
a->ops->stats_update(a, bytes, packets, lastuse);
#endif
}
#endif