lkml.org 
[lkml]   [2008]   [Feb]   [20]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
DateWed, 20 Feb 2008 15:46:29 +0100
FromPeter Zijlstra <>
Subject[PATCH 19/28] netvm: prevent a stream specific deadlock
It could happen that all !SOCK_MEMALLOC sockets have buffered so much data
that we're over the global rmem limit. This will prevent SOCK_MEMALLOC buffers
from receiving data, which will prevent userspace from running, which is needed
to reduce the buffered data.

Fix this by exempting the SOCK_MEMALLOC sockets from the rmem limit.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 include/net/sock.h   |    7 ++++---
 net/core/sock.c      |    2 +-
 net/ipv4/tcp_input.c |    8 ++++----
 net/sctp/ulpevent.c  |    2 +-
 4 files changed, 10 insertions(+), 9 deletions(-)
Index: linux-2.6/include/net/sock.h
===================================================================
--- linux-2.6.orig/include/net/sock.h
+++ linux-2.6/include/net/sock.h
@@ -791,12 +791,13 @@ static inline int sk_wmem_schedule(struc
 		__sk_mem_schedule(sk, size, SK_MEM_SEND);
 }
 
-static inline int sk_rmem_schedule(struct sock *sk, int size)
+static inline int sk_rmem_schedule(struct sock *sk, struct sk_buff *skb)
 {
 	if (!sk_has_account(sk))
 		return 1;
-	return size <= sk->sk_forward_alloc ||
-		__sk_mem_schedule(sk, size, SK_MEM_RECV);
+	return skb->truesize <= sk->sk_forward_alloc ||
+		__sk_mem_schedule(sk, skb->truesize, SK_MEM_RECV) ||
+		skb_emergency(skb);
 }
 
 static inline void sk_mem_reclaim(struct sock *sk)
Index: linux-2.6/net/core/sock.c
===================================================================
--- linux-2.6.orig/net/core/sock.c
+++ linux-2.6/net/core/sock.c
@@ -388,7 +388,7 @@ int sock_queue_rcv_skb(struct sock *sk, 
 	if (err)
 		goto out;
 
-	if (!sk_rmem_schedule(sk, skb->truesize)) {
+	if (!sk_rmem_schedule(sk, skb)) {
 		err = -ENOBUFS;
 		goto out;
 	}
Index: linux-2.6/net/ipv4/tcp_input.c
===================================================================
--- linux-2.6.orig/net/ipv4/tcp_input.c
+++ linux-2.6/net/ipv4/tcp_input.c
@@ -3858,9 +3858,9 @@ static void tcp_data_queue(struct sock *
 queue_and_out:
 			if (eaten < 0 &&
 			    (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
-			     !sk_rmem_schedule(sk, skb->truesize))) {
+			     !sk_rmem_schedule(sk, skb))) {
 				if (tcp_prune_queue(sk) < 0 ||
-				    !sk_rmem_schedule(sk, skb->truesize))
+				    !sk_rmem_schedule(sk, skb))
 					goto drop;
 			}
 			skb_set_owner_r(skb, sk);
@@ -3932,9 +3932,9 @@ drop:
 	TCP_ECN_check_ce(tp, skb);
 
 	if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
-	    !sk_rmem_schedule(sk, skb->truesize)) {
+	    !sk_rmem_schedule(sk, skb)) {
 		if (tcp_prune_queue(sk) < 0 ||
-		    !sk_rmem_schedule(sk, skb->truesize))
+		    !sk_rmem_schedule(sk, skb))
 			goto drop;
 	}
 
Index: linux-2.6/net/sctp/ulpevent.c
===================================================================
--- linux-2.6.orig/net/sctp/ulpevent.c
+++ linux-2.6/net/sctp/ulpevent.c
@@ -701,7 +701,7 @@ struct sctp_ulpevent *sctp_ulpevent_make
 	if (rx_count >= asoc->base.sk->sk_rcvbuf) {
 
 		if ((asoc->base.sk->sk_userlocks & SOCK_RCVBUF_LOCK) ||
-		    (!sk_rmem_schedule(asoc->base.sk, chunk->skb->truesize)))
+		    (!sk_rmem_schedule(asoc->base.sk, chunk->skb)))
 			goto fail;
 	}
 
--

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2008-02-20 16:29    [from the cache]
©2003-2008