diff options
| author | David S. Miller <davem@davemloft.net> | 2010-08-25 02:27:49 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-09-26 17:18:13 -0700 |
| commit | fd31b5dcb8c69c007705caa9dccdaa371f21b4f0 (patch) | |
| tree | fc4aeff76ffcbfb463f601def7190062e4dcae78 /net | |
| parent | 515b723e04cb4df7f96c59dee019d126df707fc0 (diff) | |
tcp: Combat per-cpu skew in orphan tests.
[ Upstream commit ad1af0fedba14f82b240a03fe20eb9b2fdbd0357 ]
As reported by Anton Blanchard when we use
percpu_counter_read_positive() to make our orphan socket limit checks,
the check can be off by up to num_cpus_online() * batch (which is 32
by default) which on a 128 cpu machine can be as large as the default
orphan limit itself.
Fix this by doing the full expensive sum check if the optimized check
triggers.
Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp.c | 5 | ||||
| -rw-r--r-- | net/ipv4/tcp_timer.c | 8 |
2 files changed, 5 insertions, 8 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index c259714c559..dfe12d6bad9 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2002,11 +2002,8 @@ adjudge_to_death: } } if (sk->sk_state != TCP_CLOSE) { - int orphan_count = percpu_counter_read_positive( - sk->sk_prot->orphan_count); - sk_mem_reclaim(sk); - if (tcp_too_many_orphans(sk, orphan_count)) { + if (tcp_too_many_orphans(sk, 0)) { if (net_ratelimit()) printk(KERN_INFO "TCP: too many of orphaned " "sockets\n"); diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 440a5c6004f..7abd922b205 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -67,18 +67,18 @@ static void tcp_write_err(struct sock *sk) static int tcp_out_of_resources(struct sock *sk, int do_reset) { struct tcp_sock *tp = tcp_sk(sk); - int orphans = percpu_counter_read_positive(&tcp_orphan_count); + int shift = 0; /* If peer does not open window for long time, or did not transmit * anything for long time, penalize it. */ if ((s32)(tcp_time_stamp - tp->lsndtime) > 2*TCP_RTO_MAX || !do_reset) - orphans <<= 1; + shift++; /* If some dubious ICMP arrived, penalize even more. */ if (sk->sk_err_soft) - orphans <<= 1; + shift++; - if (tcp_too_many_orphans(sk, orphans)) { + if (tcp_too_many_orphans(sk, shift)) { if (net_ratelimit()) printk(KERN_INFO "Out of socket memory\n"); |