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From: Simon Horman <horms@verge.net.au>
To: Eric Dumazet <eric.dumazet@gmail.com>,
	Julian Anastasov <ja@ssi.bg>, Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: lvs-devel@vger.kernel.org, netdev@vger.kernel.org,
	netfilter-devel@vger.kernel.org, linux-kernel@vger.kernel.org,
	Pablo Neira Ayuso <pablo@netfilter.org>,
	Dipankar Sarma <dipankar@in.ibm.com>,
	Simon Horman <horms@verge.net.au>, Ingo Molnar <mingo@kernel.org>
Subject: [PATCH v3 2/2] ipvs: Use cond_resched_rcu_lock() helper when dumping connections
Date: Wed,  1 May 2013 17:57:53 +0900	[thread overview]
Message-ID: <1367398673-1253-3-git-send-email-horms@verge.net.au> (raw)
In-Reply-To: <1367398673-1253-1-git-send-email-horms@verge.net.au>

This avoids the situation where a dump of a large number of connections
may prevent scheduling for a long time while also avoiding excessive
calls to rcu_read_unlock() and rcu_read_lock().

Note that in the case of !CONFIG_PREEMPT_RCU this will
add a call to cond_resched().

Compile tested only.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Simon Horman <horms@verge.net.au>
---
 net/netfilter/ipvs/ip_vs_conn.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c
index a083bda..42a7b33 100644
--- a/net/netfilter/ipvs/ip_vs_conn.c
+++ b/net/netfilter/ipvs/ip_vs_conn.c
@@ -975,8 +975,7 @@ static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
 				return cp;
 			}
 		}
-		rcu_read_unlock();
-		rcu_read_lock();
+		cond_resched_rcu_lock();
 	}
 
 	return NULL;
@@ -1015,8 +1014,7 @@ static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 			iter->l = &ip_vs_conn_tab[idx];
 			return cp;
 		}
-		rcu_read_unlock();
-		rcu_read_lock();
+		cond_resched_rcu_lock();
 	}
 	iter->l = NULL;
 	return NULL;
-- 
1.8.2.1


      parent reply	other threads:[~2013-05-01  8:57 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-01  8:57 [PATCH v3 0/2] sched: Add cond_resched_rcu_lock() helper Simon Horman
2013-05-01  8:57 ` [PATCH v3 1/2] " Simon Horman
2013-05-01  8:57 ` Simon Horman [this message]

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