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authorEric Dumazet <eric.dumazet@gmail.com>2010-10-08 06:37:34 +0000
committerDavid S. Miller <davem@davemloft.net>2010-10-11 13:06:53 -0700
commitfc66f95c68b6d4535a0ea2ea15d5cf626e310956 (patch)
treeac3a7f08ad741a67ff683bf93e5669ddcae95ed7 /net/ipv6
parent0ed8ddf4045fcfcac36bad753dc4046118c603ec (diff)
downloadop-kernel-dev-fc66f95c68b6d4535a0ea2ea15d5cf626e310956.zip
op-kernel-dev-fc66f95c68b6d4535a0ea2ea15d5cf626e310956.tar.gz
net dst: use a percpu_counter to track entries
struct dst_ops tracks number of allocated dst in an atomic_t field, subject to high cache line contention in stress workload. Switch to a percpu_counter, to reduce number of time we need to dirty a central location. Place it on a separate cache line to avoid dirtying read only fields. Stress test : (Sending 160.000.000 UDP frames, IP route cache disabled, dual E5540 @2.53GHz, 32bit kernel, FIB_TRIE, SLUB/NUMA) Before: real 0m51.179s user 0m15.329s sys 10m15.942s After: real 0m45.570s user 0m15.525s sys 9m56.669s With a small reordering of struct neighbour fields, subject of a following patch, (to separate refcnt from other read mostly fields) real 0m41.841s user 0m15.261s sys 8m45.949s Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/route.c28
-rw-r--r--net/ipv6/xfrm6_policy.c10
2 files changed, 26 insertions, 12 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 17e2179..25661f9 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -109,7 +109,6 @@ static struct dst_ops ip6_dst_ops_template = {
.link_failure = ip6_link_failure,
.update_pmtu = ip6_rt_update_pmtu,
.local_out = __ip6_local_out,
- .entries = ATOMIC_INIT(0),
};
static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
@@ -122,7 +121,6 @@ static struct dst_ops ip6_dst_blackhole_ops = {
.destroy = ip6_dst_destroy,
.check = ip6_dst_check,
.update_pmtu = ip6_rt_blackhole_update_pmtu,
- .entries = ATOMIC_INIT(0),
};
static struct rt6_info ip6_null_entry_template = {
@@ -1058,19 +1056,22 @@ static int ip6_dst_gc(struct dst_ops *ops)
int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
+ int entries;
+ entries = dst_entries_get_fast(ops);
if (time_after(rt_last_gc + rt_min_interval, now) &&
- atomic_read(&ops->entries) <= rt_max_size)
+ entries <= rt_max_size)
goto out;
net->ipv6.ip6_rt_gc_expire++;
fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net);
net->ipv6.ip6_rt_last_gc = now;
- if (atomic_read(&ops->entries) < ops->gc_thresh)
+ entries = dst_entries_get_slow(ops);
+ if (entries < ops->gc_thresh)
net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;
out:
net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity;
- return atomic_read(&ops->entries) > rt_max_size;
+ return entries > rt_max_size;
}
/* Clean host part of a prefix. Not necessary in radix tree,
@@ -2524,7 +2525,7 @@ static int rt6_stats_seq_show(struct seq_file *seq, void *v)
net->ipv6.rt6_stats->fib_rt_alloc,
net->ipv6.rt6_stats->fib_rt_entries,
net->ipv6.rt6_stats->fib_rt_cache,
- atomic_read(&net->ipv6.ip6_dst_ops.entries),
+ dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
net->ipv6.rt6_stats->fib_discarded_routes);
return 0;
@@ -2666,11 +2667,14 @@ static int __net_init ip6_route_net_init(struct net *net)
memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
sizeof(net->ipv6.ip6_dst_ops));
+ if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
+ goto out_ip6_dst_ops;
+
net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
sizeof(*net->ipv6.ip6_null_entry),
GFP_KERNEL);
if (!net->ipv6.ip6_null_entry)
- goto out_ip6_dst_ops;
+ goto out_ip6_dst_entries;
net->ipv6.ip6_null_entry->dst.path =
(struct dst_entry *)net->ipv6.ip6_null_entry;
net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
@@ -2720,6 +2724,8 @@ out_ip6_prohibit_entry:
out_ip6_null_entry:
kfree(net->ipv6.ip6_null_entry);
#endif
+out_ip6_dst_entries:
+ dst_entries_destroy(&net->ipv6.ip6_dst_ops);
out_ip6_dst_ops:
goto out;
}
@@ -2758,10 +2764,14 @@ int __init ip6_route_init(void)
if (!ip6_dst_ops_template.kmem_cachep)
goto out;
- ret = register_pernet_subsys(&ip6_route_net_ops);
+ ret = dst_entries_init(&ip6_dst_blackhole_ops);
if (ret)
goto out_kmem_cache;
+ ret = register_pernet_subsys(&ip6_route_net_ops);
+ if (ret)
+ goto out_dst_entries;
+
ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
/* Registering of the loopback is done before this portion of code,
@@ -2808,6 +2818,8 @@ out_fib6_init:
fib6_gc_cleanup();
out_register_subsys:
unregister_pernet_subsys(&ip6_route_net_ops);
+out_dst_entries:
+ dst_entries_destroy(&ip6_dst_blackhole_ops);
out_kmem_cache:
kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
goto out;
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 39676ea..7e74023 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -199,7 +199,7 @@ static inline int xfrm6_garbage_collect(struct dst_ops *ops)
struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops);
xfrm6_policy_afinfo.garbage_collect(net);
- return atomic_read(&ops->entries) > ops->gc_thresh * 2;
+ return dst_entries_get_fast(ops) > ops->gc_thresh * 2;
}
static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu)
@@ -255,7 +255,6 @@ static struct dst_ops xfrm6_dst_ops = {
.ifdown = xfrm6_dst_ifdown,
.local_out = __ip6_local_out,
.gc_thresh = 1024,
- .entries = ATOMIC_INIT(0),
};
static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
@@ -312,11 +311,13 @@ int __init xfrm6_init(void)
*/
gc_thresh = FIB6_TABLE_HASHSZ * 8;
xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh;
+ dst_entries_init(&xfrm6_dst_ops);
ret = xfrm6_policy_init();
- if (ret)
+ if (ret) {
+ dst_entries_destroy(&xfrm6_dst_ops);
goto out;
-
+ }
ret = xfrm6_state_init();
if (ret)
goto out_policy;
@@ -341,4 +342,5 @@ void xfrm6_fini(void)
//xfrm6_input_fini();
xfrm6_policy_fini();
xfrm6_state_fini();
+ dst_entries_destroy(&xfrm6_dst_ops);
}
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