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ipv4: Cache routes in nexthop exception entries.

Browse Source 
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2012-07-31 15:02:02 -07:00
parent d26b3a7c4b
commit c5038a8327
3 changed files with 85 additions and 70 deletions
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1
include/net/ip_fib.h
View File

@ -55,6 +55,7 @@ struct fib_nh_exception {
u32 fnhe_pmtu;
__be32 fnhe_gw;
unsigned long fnhe_expires;
struct rtable __rcu *fnhe_rth;
unsigned long fnhe_stamp;
};

53
net/ipv4/fib_semantics.c
View File

@ -140,28 +140,7 @@ const struct fib_prop fib_props[RTN_MAX + 1] = {
},
};
static void free_nh_exceptions(struct fib_nh *nh)
{
struct fnhe_hash_bucket *hash = nh->nh_exceptions;
int i;
for (i = 0; i < FNHE_HASH_SIZE; i++) {
struct fib_nh_exception *fnhe;
fnhe = rcu_dereference_protected(hash[i].chain, 1);
while (fnhe) {
struct fib_nh_exception *next;
next = rcu_dereference_protected(fnhe->fnhe_next, 1);
kfree(fnhe);
fnhe = next;
}
}
kfree(hash);
}
static void rt_nexthop_free(struct rtable __rcu **rtp)
static void rt_fibinfo_free(struct rtable __rcu **rtp)
{
struct rtable *rt = rcu_dereference_protected(*rtp, 1);
@ -176,7 +155,31 @@ static void rt_nexthop_free(struct rtable __rcu **rtp)
dst_free(&rt->dst);
}
static void rt_nexthop_free_cpus(struct rtable __rcu * __percpu *rtp)
static void free_nh_exceptions(struct fib_nh *nh)
{
struct fnhe_hash_bucket *hash = nh->nh_exceptions;
int i;
for (i = 0; i < FNHE_HASH_SIZE; i++) {
struct fib_nh_exception *fnhe;
fnhe = rcu_dereference_protected(hash[i].chain, 1);
while (fnhe) {
struct fib_nh_exception *next;
next = rcu_dereference_protected(fnhe->fnhe_next, 1);
rt_fibinfo_free(&fnhe->fnhe_rth);
kfree(fnhe);
fnhe = next;
}
}
kfree(hash);
}
static void rt_fibinfo_free_cpus(struct rtable __rcu * __percpu *rtp)
{
int cpu;
@ -203,8 +206,8 @@ static void free_fib_info_rcu(struct rcu_head *head)
dev_put(nexthop_nh->nh_dev);
if (nexthop_nh->nh_exceptions)
free_nh_exceptions(nexthop_nh);
rt_nexthop_free_cpus(nexthop_nh->nh_pcpu_rth_output);
rt_nexthop_free(&nexthop_nh->nh_rth_input);
rt_fibinfo_free_cpus(nexthop_nh->nh_pcpu_rth_output);
rt_fibinfo_free(&nexthop_nh->nh_rth_input);
} endfor_nexthops(fi);
release_net(fi->fib_net);

101
net/ipv4/route.c
View File

@ -587,11 +587,17 @@ static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
build_sk_flow_key(fl4, sk);
}
static DEFINE_SEQLOCK(fnhe_seqlock);
static inline void rt_free(struct rtable *rt)
{
call_rcu(&rt->dst.rcu_head, dst_rcu_free);
}
static DEFINE_SPINLOCK(fnhe_lock);
static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
{
struct fib_nh_exception *fnhe, *oldest;
struct rtable *orig;
oldest = rcu_dereference(hash->chain);
for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
@ -599,6 +605,11 @@ static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
oldest = fnhe;
}
orig = rcu_dereference(oldest->fnhe_rth);
if (orig) {
RCU_INIT_POINTER(oldest->fnhe_rth, NULL);
rt_free(orig);
}
return oldest;
}
@ -620,7 +631,7 @@ static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
int depth;
u32 hval = fnhe_hashfun(daddr);
write_seqlock_bh(&fnhe_seqlock);
spin_lock_bh(&fnhe_lock);
hash = nh->nh_exceptions;
if (!hash) {
@ -667,7 +678,7 @@ static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
fnhe->fnhe_stamp = jiffies;
out_unlock:
write_sequnlock_bh(&fnhe_seqlock);
spin_unlock_bh(&fnhe_lock);
return;
}
@ -1167,41 +1178,40 @@ static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
static void rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
__be32 daddr)
{
__be32 fnhe_daddr, gw;
unsigned long expires;
unsigned int seq;
u32 pmtu;
spin_lock_bh(&fnhe_lock);
restart:
seq = read_seqbegin(&fnhe_seqlock);
fnhe_daddr = fnhe->fnhe_daddr;
gw = fnhe->fnhe_gw;
pmtu = fnhe->fnhe_pmtu;
expires = fnhe->fnhe_expires;
if (read_seqretry(&fnhe_seqlock, seq))
goto restart;
if (daddr == fnhe->fnhe_daddr) {
struct rtable *orig;
if (daddr != fnhe_daddr)
return;
if (fnhe->fnhe_pmtu) {
unsigned long expires = fnhe->fnhe_expires;
unsigned long diff = expires - jiffies;
if (pmtu) {
unsigned long diff = expires - jiffies;
if (time_before(jiffies, expires)) {
rt->rt_pmtu = pmtu;
dst_set_expires(&rt->dst, diff);
if (time_before(jiffies, expires)) {
rt->rt_pmtu = fnhe->fnhe_pmtu;
dst_set_expires(&rt->dst, diff);
}
}
if (fnhe->fnhe_gw) {
rt->rt_flags |= RTCF_REDIRECTED;
rt->rt_gateway = fnhe->fnhe_gw;
}
}
if (gw) {
rt->rt_flags |= RTCF_REDIRECTED;
rt->rt_gateway = gw;
}
fnhe->fnhe_stamp = jiffies;
}
static inline void rt_free(struct rtable *rt)
{
call_rcu(&rt->dst.rcu_head, dst_rcu_free);
orig = rcu_dereference(fnhe->fnhe_rth);
rcu_assign_pointer(fnhe->fnhe_rth, rt);
if (orig)
rt_free(orig);
fnhe->fnhe_stamp = jiffies;
} else {
/* Routes we intend to cache in nexthop exception have
* the DST_NOCACHE bit clear. However, if we are
* unsuccessful at storing this route into the cache
* we really need to set it.
*/
rt->dst.flags |= DST_NOCACHE;
}
spin_unlock_bh(&fnhe_lock);
}
static void rt_cache_route(struct fib_nh *nh, struct rtable *rt)
@ -1249,13 +1259,13 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK)
rt->rt_gateway = nh->nh_gw;
if (unlikely(fnhe))
rt_bind_exception(rt, fnhe, daddr);
dst_init_metrics(&rt->dst, fi->fib_metrics, true);
#ifdef CONFIG_IP_ROUTE_CLASSID
rt->dst.tclassid = nh->nh_tclassid;
#endif
if (!(rt->dst.flags & DST_NOCACHE))
if (unlikely(fnhe))
rt_bind_exception(rt, fnhe, daddr);
else if (!(rt->dst.flags & DST_NOCACHE))
rt_cache_route(nh, rt);
}
@ -1753,22 +1763,23 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
fnhe = NULL;
if (fi) {
fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr);
if (!fnhe && FIB_RES_NH(*res).nh_pcpu_rth_output) {
struct rtable __rcu **prth;
struct rtable __rcu **prth;
fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr);
if (fnhe)
prth = &fnhe->fnhe_rth;
else
prth = __this_cpu_ptr(FIB_RES_NH(*res).nh_pcpu_rth_output);
rth = rcu_dereference(*prth);
if (rt_cache_valid(rth)) {
dst_hold(&rth->dst);
return rth;
}
rth = rcu_dereference(*prth);
if (rt_cache_valid(rth)) {
dst_hold(&rth->dst);
return rth;
}
}
rth = rt_dst_alloc(dev_out,
IN_DEV_CONF_GET(in_dev, NOPOLICY),
IN_DEV_CONF_GET(in_dev, NOXFRM),
fi && !fnhe);
fi);
if (!rth)
return ERR_PTR(-ENOBUFS);