Home » Mailing lists » Users » Networkproblem: VE stops sending ACKs
| Re: Networkproblem: VE stops sending ACKs [message #9018 is a reply to message #8693] |
Wed, 13 December 2006 12:54  |
dev
Messages: 1693
Registered: September 2005
Location: Moscow
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Senior Member |
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Konstantin,
can you please check the patch attached whether it helps?
Thanks,
Kirill
> On Saturday 02 December 2006 01:43, Konstantin Seiler wrote:
>
>>I've got a strange networkingproblem around here - the VE suddenly stops to
>>send ACKs.
>
>
> Hi!
> I finally found something related to that problem. It seems to be a problem
> with TCPRCVBUF in the VEs config. For a check I multiplied the values by 10
> and the download went fine.
> (By the way, what are considered proper values - the defaults caused the
> trouble)
>
> So I interpret the situation as a Bug of OpenVZ: The VE doesn't take TCPRCVBUF
> into account when setting the TCP-Window-Size and the propagated window is
> too big for the available buffer.
> If a packet gets lost now, the connection is doomed to die: The sender keeps
> sending packets and eventually the buffer is full. When the retransmission of
> the lost packet finally arrives, it is discarded because of the full buffer
> and the connection is in a deadlock.
> The retransmission can't be accepted because of the full buffer and the buffer
> can't be emptied, because a packet is missing.
>
> Cheers,
> Konstantin
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 0ff49a5..7e8f200 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1815,8 +1815,9 @@ static inline int tcp_win_from_space(int
/* Note: caller must be prepared to deal with negative returns */
static inline int tcp_space(const struct sock *sk)
{
- return tcp_win_from_space(sk->sk_rcvbuf -
- atomic_read(&sk->sk_rmem_alloc));
+ int ub_tcp_rcvbuf = (int) sock_bc(sk)->ub_tcp_rcvbuf;
+ return tcp_win_from_space(min(sk->sk_rcvbuf, ub_tcp_rcvbuf)
+ - atomic_read(&sk->sk_rmem_alloc));
}
static inline int tcp_full_space(const struct sock *sk)
diff --git a/include/ub/beancounter.h b/include/ub/beancounter.h
index 3d87afa..fc236e8 100644
--- a/include/ub/beancounter.h
+++ b/include/ub/beancounter.h
@@ -144,6 +144,8 @@ struct sock_private {
unsigned long ubp_rmem_thres;
unsigned long ubp_wmem_pressure;
unsigned long ubp_maxadvmss;
+ /* Total size of all advertised receive windows for all tcp sockets */
+ unsigned long ubp_rcv_wnd;
unsigned long ubp_rmem_pressure;
#define UB_RMEM_EXPAND 0
#define UB_RMEM_KEEP 1
@@ -177,6 +179,7 @@ #define ub_held_pages ppriv.ubp_held_pa
struct sock_private spriv;
#define ub_rmem_thres spriv.ubp_rmem_thres
#define ub_maxadvmss spriv.ubp_maxadvmss
+#define ub_rcv_wnd spriv.ubp_rcv_wnd
#define ub_rmem_pressure spriv.ubp_rmem_pressure
#define ub_wmem_pressure spriv.ubp_wmem_pressure
#define ub_tcp_sk_list spriv.ubp_tcp_socks
diff --git a/include/ub/ub_sk.h b/include/ub/ub_sk.h
index e65c9ed..02d0137 100644
--- a/include/ub/ub_sk.h
+++ b/include/ub/ub_sk.h
@@ -34,6 +34,8 @@ struct sock_beancounter {
*/
unsigned long poll_reserv;
unsigned long forw_space;
+ unsigned long ub_tcp_rcvbuf;
+ unsigned long ub_rcv_wnd_old;
/* fields below are protected by bc spinlock */
unsigned long ub_waitspc; /* space waiting for */
unsigned long ub_wcharged;
diff --git a/kernel/ub/ub_net.c b/kernel/ub/ub_net.c
index 74d651a..afee710 100644
--- a/kernel/ub/ub_net.c
+++ b/kernel/ub/ub_net.c
@@ -420,6 +420,7 @@ static int __sock_charge(struct sock *sk
added_reserv = 0;
added_forw = 0;
+ skbc->ub_rcv_wnd_old = 0;
if (res == UB_NUMTCPSOCK) {
added_reserv = skb_charge_size(MAX_TCP_HEADER +
1500 - sizeof(struct iphdr) -
@@ -439,6 +440,7 @@ static int __sock_charge(struct sock *sk
added_forw = 0;
}
skbc->forw_space = added_forw;
+ skbc->ub_tcp_rcvbuf = added_forw + SK_STREAM_MEM_QUANTUM;
}
spin_unlock_irqrestore(&ub->ub_lock, flags);
@@ -528,6 +530,7 @@ void ub_sock_uncharge(struct sock *sk)
skbc->ub_wcharged, skbc->ub, skbc->ub->ub_uid);
skbc->poll_reserv = 0;
skbc->forw_space = 0;
+ ub->ub_rcv_wnd -= is_tcp_sock ? tcp_sk(sk)->rcv_wnd : 0;
spin_unlock_irqrestore(&ub->ub_lock, flags);
uncharge_beancounter_notop(skbc->ub,
@@ -768,6 +771,44 @@ static void ub_sockrcvbuf_uncharge(struc
* UB_TCPRCVBUF
*/
+/*
+ * UBC TCP window management mechanism.
+ * Every socket may consume no more than sock_quantum.
+ * sock_quantum depends on space available and ub_parms[UB_NUMTCPSOCK].held.
+ */
+static void ub_sock_tcp_update_rcvbuf(struct user_beancounter *ub,
+ struct sock *sk)
+{
+ unsigned long allowed;
+ unsigned long reserved;
+ unsigned long available;
+ unsigned long sock_quantum;
+ struct tcp_opt *tp = tcp_sk(sk);
+ struct sock_beancounter *skbc;
+ skbc = sock_bc(sk);
+
+ if( ub->ub_parms[UB_NUMTCPSOCK].limit * ub->ub_maxadvmss
+ > ub->ub_parms[UB_TCPRCVBUF].limit) {
+ /* this is defenitly shouldn't happend */
+ return;
+ }
+ allowed = ub->ub_parms[UB_TCPRCVBUF].barrier;
+ ub->ub_rcv_wnd += (tp->rcv_wnd - skbc->ub_rcv_wnd_old);
+ skbc->ub_rcv_wnd_old = tp->rcv_wnd;
+ reserved = ub->ub_parms[UB_TCPRCVBUF].held + ub->ub_rcv_wnd;
+ available = (allowed < reserved)?
+ 0:allowed - reserved;
+ sock_quantum = max(allowed / ub->ub_parms[UB_NUMTCPSOCK].held,
+ ub->ub_maxadvmss);
+ if ( skbc->ub_tcp_rcvbuf > sock_quantum) {
+ skbc->ub_tcp_rcvbuf = sock_quantum;
+ } else {
+ skbc->ub_tcp_rcvbuf += min(sock_quantum - skbc->ub_tcp_rcvbuf,
+ available);
+ }
+
+}
+
int ub_sock_tcp_chargerecv(struct sock *sk, struct sk_buff *skb,
enum ub_severity strict)
{
@@ -804,6 +845,7 @@ int ub_sock_tcp_chargerecv(struct sock *
retval = 0;
for (ub = sock_bc(sk)->ub; ub->parent != NULL; ub = ub->parent);
spin_lock_irqsave(&ub->ub_lock, flags);
+ ub_sock_tcp_update_rcvbuf(ub, sk);
ub->ub_parms[UB_TCPRCVBUF].held += chargesize;
if (ub->ub_parms[UB_TCPRCVBUF].held >
ub->ub_parms[UB_TCPRCVBUF].barrier &&
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