diff options
| author | Wu Fengguang <fengguang.wu@intel.com> | 2009-09-02 23:45:45 -0700 | 
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-09-02 23:45:45 -0700 | 
| commit | aa1330766c49199bdab4d4a9096d98b072df9044 (patch) | |
| tree | 98787478dbef0faa7caee09c4996abcda723a608 /net/ipv4/tcp_output.c | |
| parent | 05c6a8d7a7d778f26d8eb821556988993b766092 (diff) | |
| download | olio-linux-3.10-aa1330766c49199bdab4d4a9096d98b072df9044.tar.xz olio-linux-3.10-aa1330766c49199bdab4d4a9096d98b072df9044.zip  | |
tcp: replace hard coded GFP_KERNEL with sk_allocation
This fixed a lockdep warning which appeared when doing stress
memory tests over NFS:
	inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
	page reclaim => nfs_writepage => tcp_sendmsg => lock sk_lock
	mount_root => nfs_root_data => tcp_close => lock sk_lock =>
			tcp_send_fin => alloc_skb_fclone => page reclaim
David raised a concern that if the allocation fails in tcp_send_fin(), and it's
GFP_ATOMIC, we are going to yield() (which sleeps) and loop endlessly waiting
for the allocation to succeed.
But fact is, the original GFP_KERNEL also sleeps. GFP_ATOMIC+yield() looks
weird, but it is no worse the implicit sleep inside GFP_KERNEL. Both could
loop endlessly under memory pressure.
CC: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
CC: David S. Miller <davem@davemloft.net>
CC: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 5 | 
1 files changed, 3 insertions, 2 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 4e004424d40..5200aab0ca9 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2135,7 +2135,8 @@ void tcp_send_fin(struct sock *sk)  	} else {  		/* Socket is locked, keep trying until memory is available. */  		for (;;) { -			skb = alloc_skb_fclone(MAX_TCP_HEADER, GFP_KERNEL); +			skb = alloc_skb_fclone(MAX_TCP_HEADER, +					       sk->sk_allocation);  			if (skb)  				break;  			yield(); @@ -2388,7 +2389,7 @@ int tcp_connect(struct sock *sk)  	sk->sk_wmem_queued += buff->truesize;  	sk_mem_charge(sk, buff->truesize);  	tp->packets_out += tcp_skb_pcount(buff); -	tcp_transmit_skb(sk, buff, 1, GFP_KERNEL); +	tcp_transmit_skb(sk, buff, 1, sk->sk_allocation);  	/* We change tp->snd_nxt after the tcp_transmit_skb() call  	 * in order to make this packet get counted in tcpOutSegs.  |