[SCTP]: Rewrite of sctp buffer management code
This patch introduces autotuning to the sctp buffer management code
similar to the TCP. The buffer space can be grown if the advertised
receive window still has room. This might happen if small message
sizes are used, which is common in telecom environmens.
New tunables are introduced that provide limits to buffer growth
and memory pressure is entered if to much buffer spaces is used.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 772fbfb..b995242 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -107,23 +107,42 @@
struct sctp_association *, sctp_socket_type_t);
static char *sctp_hmac_alg = SCTP_COOKIE_HMAC_ALG;
+extern struct kmem_cache *sctp_bucket_cachep;
+extern int sysctl_sctp_mem[3];
+extern int sysctl_sctp_rmem[3];
+extern int sysctl_sctp_wmem[3];
+
+int sctp_memory_pressure;
+atomic_t sctp_memory_allocated;
+atomic_t sctp_sockets_allocated;
+
+static void sctp_enter_memory_pressure(void)
+{
+ sctp_memory_pressure = 1;
+}
+
+
/* Get the sndbuf space available at the time on the association. */
static inline int sctp_wspace(struct sctp_association *asoc)
{
- struct sock *sk = asoc->base.sk;
- int amt = 0;
+ int amt;
- if (asoc->ep->sndbuf_policy) {
- /* make sure that no association uses more than sk_sndbuf */
- amt = sk->sk_sndbuf - asoc->sndbuf_used;
+ if (asoc->ep->sndbuf_policy)
+ amt = asoc->sndbuf_used;
+ else
+ amt = atomic_read(&asoc->base.sk->sk_wmem_alloc);
+
+ if (amt >= asoc->base.sk->sk_sndbuf) {
+ if (asoc->base.sk->sk_userlocks & SOCK_SNDBUF_LOCK)
+ amt = 0;
+ else {
+ amt = sk_stream_wspace(asoc->base.sk);
+ if (amt < 0)
+ amt = 0;
+ }
} else {
- /* do socket level accounting */
- amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
+ amt = asoc->base.sk->sk_sndbuf - amt;
}
-
- if (amt < 0)
- amt = 0;
-
return amt;
}
@@ -155,6 +174,7 @@
sizeof(struct sctp_chunk);
atomic_add(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
+ sk_charge_skb(sk, chunk->skb);
}
/* Verify that this is a valid address. */
@@ -3293,6 +3313,7 @@
sp->hmac = NULL;
SCTP_DBG_OBJCNT_INC(sock);
+ atomic_inc(&sctp_sockets_allocated);
return 0;
}
@@ -3306,7 +3327,7 @@
/* Release our hold on the endpoint. */
ep = sctp_sk(sk)->ep;
sctp_endpoint_free(ep);
-
+ atomic_dec(&sctp_sockets_allocated);
return 0;
}
@@ -5720,6 +5741,12 @@
atomic_sub(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
+ /*
+ * This undoes what is done via sk_charge_skb
+ */
+ sk->sk_wmem_queued -= skb->truesize;
+ sk->sk_forward_alloc += skb->truesize;
+
sock_wfree(skb);
__sctp_write_space(asoc);
@@ -5737,6 +5764,11 @@
struct sctp_ulpevent *event = sctp_skb2event(skb);
atomic_sub(event->rmem_len, &sk->sk_rmem_alloc);
+
+ /*
+ * Mimic the behavior of sk_stream_rfree
+ */
+ sk->sk_forward_alloc += event->rmem_len;
}
@@ -6126,6 +6158,7 @@
sctp_release_sock(newsk);
}
+
/* This proto struct describes the ULP interface for SCTP. */
struct proto sctp_prot = {
.name = "SCTP",
@@ -6148,6 +6181,12 @@
.unhash = sctp_unhash,
.get_port = sctp_get_port,
.obj_size = sizeof(struct sctp_sock),
+ .sysctl_mem = sysctl_sctp_mem,
+ .sysctl_rmem = sysctl_sctp_rmem,
+ .sysctl_wmem = sysctl_sctp_wmem,
+ .memory_pressure = &sctp_memory_pressure,
+ .enter_memory_pressure = sctp_enter_memory_pressure,
+ .memory_allocated = &sctp_memory_allocated,
};
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -6172,5 +6211,11 @@
.unhash = sctp_unhash,
.get_port = sctp_get_port,
.obj_size = sizeof(struct sctp6_sock),
+ .sysctl_mem = sysctl_sctp_mem,
+ .sysctl_rmem = sysctl_sctp_rmem,
+ .sysctl_wmem = sysctl_sctp_wmem,
+ .memory_pressure = &sctp_memory_pressure,
+ .enter_memory_pressure = sctp_enter_memory_pressure,
+ .memory_allocated = &sctp_memory_allocated,
};
#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
