| Message ID | 1504044961.11498.100.camel@edumazet-glaptop3.roam.corp.google.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net-next] neigh: increase queue_len_bytes to match wmem_default | expand |
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Tue, 29 Aug 2017 15:16:01 -0700 > From: Eric Dumazet <edumazet@google.com> > > Florian reported UDP xmit drops that could be root caused to the > too small neigh limit. > > Current limit is 64 KB, meaning that even a single UDP socket would hit > it, since its default sk_sndbuf comes from net.core.wmem_default > (~212992 bytes on 64bit arches). > > Once ARP/ND resolution is in progress, we should allow a little more > packets to be queued, at least for one producer. > > Once neigh arp_queue is filled, a rogue socket should hit its sk_sndbuf > limit and either block in sendmsg() or return -EAGAIN. > > Signed-off-by: Eric Dumazet <edumazet@google.com> > Reported-by: Florian Fainelli <f.fainelli@gmail.com> Applied, thanks for following up on this.
On Tue, 2017-08-29 at 15:16 -0700, Eric Dumazet wrote: > diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c > index > 568ccfd6dd371d88136ffabe5cfcc36f099786b6..7616cd76f6f6a62f395da897baef2c66c0098193 100644 > --- a/net/ipv4/tcp_input.c > +++ b/net/ipv4/tcp_input.c > @@ -6086,9 +6086,9 @@ int tcp_conn_request(struct request_sock_ops > *rsk_ops, > struct tcp_sock *tp = tcp_sk(sk); > struct net *net = sock_net(sk); > struct sock *fastopen_sk = NULL; > - struct dst_entry *dst = NULL; > struct request_sock *req; > bool want_cookie = false; > + struct dst_entry *dst; > struct flowi fl; > > /* TW buckets are converted to open req This part was meant to belong to a separate patch :/ No big deal, this was also one of your suggestion David.
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Tue, 29 Aug 2017 16:15:28 -0700 > On Tue, 2017-08-29 at 15:16 -0700, Eric Dumazet wrote: >> diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c >> index >> 568ccfd6dd371d88136ffabe5cfcc36f099786b6..7616cd76f6f6a62f395da897baef2c66c0098193 100644 >> --- a/net/ipv4/tcp_input.c >> +++ b/net/ipv4/tcp_input.c >> @@ -6086,9 +6086,9 @@ int tcp_conn_request(struct request_sock_ops >> *rsk_ops, >> struct tcp_sock *tp = tcp_sk(sk); >> struct net *net = sock_net(sk); >> struct sock *fastopen_sk = NULL; >> - struct dst_entry *dst = NULL; >> struct request_sock *req; >> bool want_cookie = false; >> + struct dst_entry *dst; >> struct flowi fl; >> >> /* TW buckets are converted to open req > > This part was meant to belong to a separate patch :/ > > No big deal, this was also one of your suggestion David. Yeah, no big deal. But thanks for pointing it out.
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 6b0bc0f715346a097a6df46e2ba2771359abcd23..b3345d0fe0a67e477a6754848e7fc7be144322d5 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -109,7 +109,10 @@ neigh/default/unres_qlen_bytes - INTEGER queued for each unresolved address by other network layers. (added in linux 3.3) Setting negative value is meaningless and will return error. - Default: 65536 Bytes(64KB) + Default: SK_WMEM_MAX, (same as net.core.wmem_default). + Exact value depends on architecture and kernel options, + but should be enough to allow queuing 256 packets + of medium size. neigh/default/unres_qlen - INTEGER The maximum number of packets which may be queued for each @@ -119,7 +122,7 @@ neigh/default/unres_qlen - INTEGER unexpected packet loss. The current default value is calculated according to default value of unres_qlen_bytes and true size of packet. - Default: 31 + Default: 101 mtu_expires - INTEGER Time, in seconds, that cached PMTU information is kept. diff --git a/include/net/sock.h b/include/net/sock.h index 1c2912d433e81b10f3fdc87bcfcbb091570edc03..03a362568357acc7278a318423dd3873103f90ca 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2368,6 +2368,16 @@ bool sk_net_capable(const struct sock *sk, int cap); void sk_get_meminfo(const struct sock *sk, u32 *meminfo); +/* Take into consideration the size of the struct sk_buff overhead in the + * determination of these values, since that is non-constant across + * platforms. This makes socket queueing behavior and performance + * not depend upon such differences. + */ +#define _SK_MEM_PACKETS 256 +#define _SK_MEM_OVERHEAD SKB_TRUESIZE(256) +#define SK_WMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS) +#define SK_RMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS) + extern __u32 sysctl_wmem_max; extern __u32 sysctl_rmem_max; diff --git a/net/core/sock.c b/net/core/sock.c index dfdd14cac775e9bfcee0085ee32ffcd0ab28b67b..9b7b6bbb2a23e7652a1f34a305f29d49de00bc8c 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -307,16 +307,6 @@ static struct lock_class_key af_wlock_keys[AF_MAX]; static struct lock_class_key af_elock_keys[AF_MAX]; static struct lock_class_key af_kern_callback_keys[AF_MAX]; -/* Take into consideration the size of the struct sk_buff overhead in the - * determination of these values, since that is non-constant across - * platforms. This makes socket queueing behavior and performance - * not depend upon such differences. - */ -#define _SK_MEM_PACKETS 256 -#define _SK_MEM_OVERHEAD SKB_TRUESIZE(256) -#define SK_WMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS) -#define SK_RMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS) - /* Run time adjustable parameters. */ __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX; EXPORT_SYMBOL(sysctl_wmem_max); diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c index 21dedf6fd0f76dec22b2b3685beb89cfefea7ded..22bf0b95d6edc3c27ef3a99d27cb70a1551e3e0e 100644 --- a/net/decnet/dn_neigh.c +++ b/net/decnet/dn_neigh.c @@ -94,7 +94,7 @@ struct neigh_table dn_neigh_table = { [NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ, [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ, [NEIGH_VAR_GC_STALETIME] = 60 * HZ, - [NEIGH_VAR_QUEUE_LEN_BYTES] = 64*1024, + [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX, [NEIGH_VAR_PROXY_QLEN] = 0, [NEIGH_VAR_ANYCAST_DELAY] = 0, [NEIGH_VAR_PROXY_DELAY] = 0, diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index 8b52179ddc6e54eabf6d3c2ed0132083228680bb..7c45b8896709815c5dde5972fd57cb5c3bcb2648 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -171,7 +171,7 @@ struct neigh_table arp_tbl = { [NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ, [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ, [NEIGH_VAR_GC_STALETIME] = 60 * HZ, - [NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024, + [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX, [NEIGH_VAR_PROXY_QLEN] = 64, [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ, [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10, diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 568ccfd6dd371d88136ffabe5cfcc36f099786b6..7616cd76f6f6a62f395da897baef2c66c0098193 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6086,9 +6086,9 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, struct tcp_sock *tp = tcp_sk(sk); struct net *net = sock_net(sk); struct sock *fastopen_sk = NULL; - struct dst_entry *dst = NULL; struct request_sock *req; bool want_cookie = false; + struct dst_entry *dst; struct flowi fl; /* TW buckets are converted to open requests without diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 5e338eb89509b1df6ebd060f8bd19fcb4b86fe05..266a530414d7be4f1e7be922e465bbab46f7cbac 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -127,7 +127,7 @@ struct neigh_table nd_tbl = { [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME, [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ, [NEIGH_VAR_GC_STALETIME] = 60 * HZ, - [NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024, + [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX, [NEIGH_VAR_PROXY_QLEN] = 64, [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ, [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,