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/stream.c | 5 +++-- 2 files changed, 7 insertions(+), 5 deletions(-) Index: linux-2.6/include/net/sock.h =================================================================== --- linux-2.6.orig/include/net/sock.h +++ linux-2.6/include/net/sock.h @@ -743,7 +743,8 @@ static inline struct inode *SOCK_INODE(s } extern void __sk_stream_mem_reclaim(struct sock *sk); -extern int sk_stream_mem_schedule(struct sock *sk, int size, int kind); +extern int sk_stream_mem_schedule(struct sock *sk, struct sk_buff *skb, + int size, int kind); #define SK_STREAM_MEM_QUANTUM ((int)PAGE_SIZE) @@ -761,13 +762,13 @@ static inline void sk_stream_mem_reclaim static inline int sk_stream_rmem_schedule(struct sock *sk, struct sk_buff *skb) { return (int)skb->truesize <= sk->sk_forward_alloc || - sk_stream_mem_schedule(sk, skb->truesize, 1); + sk_stream_mem_schedule(sk, skb, skb->truesize, 1); } static inline int sk_stream_wmem_schedule(struct sock *sk, int size) { return size <= sk->sk_forward_alloc || - sk_stream_mem_schedule(sk, size, 0); + sk_stream_mem_schedule(sk, NULL, size, 0); } /* Used by processes to "lock" a socket state, so that Index: linux-2.6/net/core/stream.c =================================================================== --- linux-2.6.orig/net/core/stream.c +++ linux-2.6/net/core/stream.c @@ -207,7 +207,7 @@ void __sk_stream_mem_reclaim(struct sock EXPORT_SYMBOL(__sk_stream_mem_reclaim); -int sk_stream_mem_schedule(struct sock *sk, int size, int kind) +int sk_stream_mem_schedule(struct sock *sk, struct sk_buff *skb, int size, int kind) { int amt = sk_stream_pages(size); @@ -224,7 +224,8 @@ int sk_stream_mem_schedule(struct sock * /* Over hard limit. */ if (atomic_read(sk->sk_prot->memory_allocated) > sk->sk_prot->sysctl_mem[2]) { sk->sk_prot->enter_memory_pressure(); - goto suppress_allocation; + if (!skb || (skb && !skb_emergency(skb))) + goto suppress_allocation; } /* Under pressure. */ -- - 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/