ipv6: remove max_size check inline with ipv4
In ip6_dst_gc() replace: if (entries > gc_thresh) With: if (entries > ops->gc_thresh) Sending Ipv6 packets in a loop via a raw socket triggers an issue where a route is cloned by ip6_rt_cache_alloc() for each packet sent. This quickly consumes the Ipv6 max_size threshold which defaults to 4096 resulting in these warnings: [1] 99.187805] dst_alloc: 7728 callbacks suppressed [2] Route cache is full: consider increasing sysctl net.ipv6.route.max_size. . . [300] Route cache is full: consider increasing sysctl net.ipv6.route.max_size. When this happens the packet is dropped and sendto() gets a network is unreachable error: remaining pkt 200557 errno 101 remaining pkt 196462 errno 101 . . remaining pkt 126821 errno 101 Implement David Aherns suggestion to remove max_size check seeing that Ipv6 has a GC to manage memory usage. Ipv4 already does not check max_size. Here are some memory comparisons for Ipv4 vs Ipv6 with the patch: Test by running 5 instances of a program that sends UDP packets to a raw socket 5000000 times. Compare Ipv4 and Ipv6 performance with a similar program. Ipv4: Before test: MemFree: 29427108 kB Slab: 237612 kB ip6_dst_cache 1912 2528 256 32 2 : tunables 0 0 0 xfrm_dst_cache 0 0 320 25 2 : tunables 0 0 0 ip_dst_cache 2881 3990 192 42 2 : tunables 0 0 0 During test: MemFree: 29417608 kB Slab: 247712 kB ip6_dst_cache 1912 2528 256 32 2 : tunables 0 0 0 xfrm_dst_cache 0 0 320 25 2 : tunables 0 0 0 ip_dst_cache 44394 44394 192 42 2 : tunables 0 0 0 After test: MemFree: 29422308 kB Slab: 238104 kB ip6_dst_cache 1912 2528 256 32 2 : tunables 0 0 0 xfrm_dst_cache 0 0 320 25 2 : tunables 0 0 0 ip_dst_cache 3048 4116 192 42 2 : tunables 0 0 0 Ipv6 with patch: Errno 101 errors are not observed anymore with the patch. Before test: MemFree: 29422308 kB Slab: 238104 kB ip6_dst_cache 1912 2528 256 32 2 : tunables 0 0 0 xfrm_dst_cache 0 0 320 25 2 : tunables 0 0 0 ip_dst_cache 3048 4116 192 42 2 : tunables 0 0 0 During Test: MemFree: 29431516 kB Slab: 240940 kB ip6_dst_cache 11980 12064 256 32 2 : tunables 0 0 0 xfrm_dst_cache 0 0 320 25 2 : tunables 0 0 0 ip_dst_cache 3048 4116 192 42 2 : tunables 0 0 0 After Test: MemFree: 29441816 kB Slab: 238132 kB ip6_dst_cache 1902 2432 256 32 2 : tunables 0 0 0 xfrm_dst_cache 0 0 320 25 2 : tunables 0 0 0 ip_dst_cache 3048 4116 192 42 2 : tunables 0 0 0 Tested-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20230112012532.311021-1-jmaxwell37@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jon Maxwell
Jakub Kicinski
parent
c191751410
commit
af6d10345c
@ -16,7 +16,7 @@ struct dst_ops {
|
||||
unsigned short family;
|
||||
unsigned int gc_thresh;
|
||||
|
||||
int (*gc)(struct dst_ops *ops);
|
||||
void (*gc)(struct dst_ops *ops);
|
||||
struct dst_entry * (*check)(struct dst_entry *, __u32 cookie);
|
||||
unsigned int (*default_advmss)(const struct dst_entry *);
|
||||
unsigned int (*mtu)(const struct dst_entry *);
|
||||
|
||||
@ -82,12 +82,8 @@ void *dst_alloc(struct dst_ops *ops, struct net_device *dev,
|
||||
|
||||
if (ops->gc &&
|
||||
!(flags & DST_NOCOUNT) &&
|
||||
dst_entries_get_fast(ops) > ops->gc_thresh) {
|
||||
if (ops->gc(ops)) {
|
||||
pr_notice_ratelimited("Route cache is full: consider increasing sysctl net.ipv6.route.max_size.\n");
|
||||
return NULL;
|
||||
}
|
||||
}
|
||||
dst_entries_get_fast(ops) > ops->gc_thresh)
|
||||
ops->gc(ops);
|
||||
|
||||
dst = kmem_cache_alloc(ops->kmem_cachep, GFP_ATOMIC);
|
||||
if (!dst)
|
||||
|
||||
@ -91,7 +91,7 @@ static struct dst_entry *ip6_negative_advice(struct dst_entry *);
|
||||
static void ip6_dst_destroy(struct dst_entry *);
|
||||
static void ip6_dst_ifdown(struct dst_entry *,
|
||||
struct net_device *dev, int how);
|
||||
static int ip6_dst_gc(struct dst_ops *ops);
|
||||
static void ip6_dst_gc(struct dst_ops *ops);
|
||||
|
||||
static int ip6_pkt_discard(struct sk_buff *skb);
|
||||
static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
|
||||
@ -3284,11 +3284,10 @@ out:
|
||||
return dst;
|
||||
}
|
||||
|
||||
static int ip6_dst_gc(struct dst_ops *ops)
|
||||
static void ip6_dst_gc(struct dst_ops *ops)
|
||||
{
|
||||
struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
|
||||
int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
|
||||
int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
|
||||
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;
|
||||
@ -3296,11 +3295,10 @@ static int ip6_dst_gc(struct dst_ops *ops)
|
||||
int entries;
|
||||
|
||||
entries = dst_entries_get_fast(ops);
|
||||
if (entries > rt_max_size)
|
||||
if (entries > ops->gc_thresh)
|
||||
entries = dst_entries_get_slow(ops);
|
||||
|
||||
if (time_after(rt_last_gc + rt_min_interval, jiffies) &&
|
||||
entries <= rt_max_size)
|
||||
if (time_after(rt_last_gc + rt_min_interval, jiffies))
|
||||
goto out;
|
||||
|
||||
fib6_run_gc(atomic_inc_return(&net->ipv6.ip6_rt_gc_expire), net, true);
|
||||
@ -3310,7 +3308,6 @@ static int ip6_dst_gc(struct dst_ops *ops)
|
||||
out:
|
||||
val = atomic_read(&net->ipv6.ip6_rt_gc_expire);
|
||||
atomic_set(&net->ipv6.ip6_rt_gc_expire, val - (val >> rt_elasticity));
|
||||
return entries > rt_max_size;
|
||||
}
|
||||
|
||||
static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
|
||||
@ -6512,7 +6509,7 @@ static int __net_init ip6_route_net_init(struct net *net)
|
||||
#endif
|
||||
|
||||
net->ipv6.sysctl.flush_delay = 0;
|
||||
net->ipv6.sysctl.ip6_rt_max_size = 4096;
|
||||
net->ipv6.sysctl.ip6_rt_max_size = INT_MAX;
|
||||
net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
|
||||
net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
|
||||
net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user