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authorHerbert Xu2008-12-30 08:04:08 +0100
committerDavid S. Miller2008-12-30 08:04:08 +0100
commiteb4dea5853046727bfbb579f0c9a8cae7369f7c6 (patch)
tree79e18d6284494ab63a890885b0eecce9431a9597 /net/ipv4/tcp.c
parentcpumask: prepare for iterators to only go to nr_cpu_ids/nr_cpumask_bits: net (diff)
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net: Fix percpu counters deadlock
When we converted the protocol atomic counters such as the orphan count and the total socket count deadlocks were introduced due to the mismatch in BH status of the spots that used the percpu counter operations. Based on the diagnosis and patch by Peter Zijlstra, this patch fixes these issues by disabling BH where we may be in process context. Reported-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp.c')
-rw-r--r--net/ipv4/tcp.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 1f3d52946b3b..f28acf11fc67 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1836,7 +1836,6 @@ adjudge_to_death:
state = sk->sk_state;
sock_hold(sk);
sock_orphan(sk);
- percpu_counter_inc(sk->sk_prot->orphan_count);
/* It is the last release_sock in its life. It will remove backlog. */
release_sock(sk);
@@ -1849,6 +1848,8 @@ adjudge_to_death:
bh_lock_sock(sk);
WARN_ON(sock_owned_by_user(sk));
+ percpu_counter_inc(sk->sk_prot->orphan_count);
+
/* Have we already been destroyed by a softirq or backlog? */
if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
goto out;