From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <20080220150307.719988000@chello.nl> References: <20080220144610.548202000@chello.nl> Date: Wed, 20 Feb 2008 15:46:29 +0100 From: Peter Zijlstra Subject: [PATCH 19/28] netvm: prevent a stream specific deadlock Content-Disposition: inline; filename=netvm-tcp-deadlock.patch Sender: owner-linux-mm@kvack.org Return-Path: To: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, trond.myklebust@fys.uio.no Cc: Peter Zijlstra List-ID: 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 --- 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org