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Message-ID: <1344842549-25923-1-git-send-email-Priyanka.Jain@freescale.com>
Date: Mon, 13 Aug 2012 12:52:29 +0530
From: Priyanka Jain <Priyanka.Jain@...escale.com>
To: <davem@...emloft.net>, <netdev@...r.kernel.org>
CC: Priyanka Jain <Priyanka.Jain@...escale.com>
Subject: [PATCH][XFRM][v3] Replace rwlock on xfrm_policy_afinfo with rcu
xfrm_policy_afinfo is read mosly data structure.
Write on xfrm_policy_afinfo is done only at the
time of configuration.
So rwlocks can be safely replaced with RCU.
RCUs usage optimizes the performance.
Signed-off-by: Priyanka Jain <Priyanka.Jain@...escale.com>
---
Changes for v3:
Replaced 'local_bh_disable;rcu_read_lock' with 'rcu_read_lock_bh' as
suggested by David
Changes for v2:
Re-spined to netdev-next & corrected indentation as suggested by David
For IPSEC fwd test
-On p4080ds (8-core, SMP system)
Around 110% throughput increase in case of PREEMPT_RT enabled
Around 5-6% throughput increase in case of PREEMPT_RT disabled
-On p2020 (2-core, SMP system)
Around 4-5% throughput increase in case of PREEMPT_RT disabled
net/xfrm/xfrm_policy.c | 39 +++++++++++++++++++++------------------
1 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index c5a5165..5ad4d2c 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -42,13 +42,14 @@ static DEFINE_SPINLOCK(xfrm_policy_sk_bundle_lock);
static struct dst_entry *xfrm_policy_sk_bundles;
static DEFINE_RWLOCK(xfrm_policy_lock);
-static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);
-static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];
+static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
+static struct xfrm_policy_afinfo __rcu *xfrm_policy_afinfo[NPROTO]
+ __read_mostly;
static struct kmem_cache *xfrm_dst_cache __read_mostly;
static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
-static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
+static inline void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
static void xfrm_init_pmtu(struct dst_entry *dst);
static int stale_bundle(struct dst_entry *dst);
static int xfrm_bundle_ok(struct xfrm_dst *xdst);
@@ -2418,7 +2419,7 @@ int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
return -EINVAL;
if (unlikely(afinfo->family >= NPROTO))
return -EAFNOSUPPORT;
- write_lock_bh(&xfrm_policy_afinfo_lock);
+ spin_lock_bh(&xfrm_policy_afinfo_lock);
if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
err = -ENOBUFS;
else {
@@ -2439,9 +2440,9 @@ int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
dst_ops->neigh_lookup = xfrm_neigh_lookup;
if (likely(afinfo->garbage_collect == NULL))
afinfo->garbage_collect = xfrm_garbage_collect_deferred;
- xfrm_policy_afinfo[afinfo->family] = afinfo;
+ rcu_assign_pointer(xfrm_policy_afinfo[afinfo->family], afinfo);
}
- write_unlock_bh(&xfrm_policy_afinfo_lock);
+ spin_unlock_bh(&xfrm_policy_afinfo_lock);
rtnl_lock();
for_each_net(net) {
@@ -2474,13 +2475,14 @@ int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
return -EINVAL;
if (unlikely(afinfo->family >= NPROTO))
return -EAFNOSUPPORT;
- write_lock_bh(&xfrm_policy_afinfo_lock);
+ spin_lock_bh(&xfrm_policy_afinfo_lock);
if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {
if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))
err = -EINVAL;
else {
struct dst_ops *dst_ops = afinfo->dst_ops;
- xfrm_policy_afinfo[afinfo->family] = NULL;
+ rcu_assign_pointer(xfrm_policy_afinfo[afinfo->family],
+ NULL);
dst_ops->kmem_cachep = NULL;
dst_ops->check = NULL;
dst_ops->negative_advice = NULL;
@@ -2488,7 +2490,8 @@ int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo)
afinfo->garbage_collect = NULL;
}
}
- write_unlock_bh(&xfrm_policy_afinfo_lock);
+ spin_unlock_bh(&xfrm_policy_afinfo_lock);
+ synchronize_rcu();
return err;
}
EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
@@ -2497,16 +2500,16 @@ static void __net_init xfrm_dst_ops_init(struct net *net)
{
struct xfrm_policy_afinfo *afinfo;
- read_lock_bh(&xfrm_policy_afinfo_lock);
- afinfo = xfrm_policy_afinfo[AF_INET];
+ rcu_read_lock_bh();
+ afinfo = rcu_dereference(xfrm_policy_afinfo[AF_INET]);
if (afinfo)
net->xfrm.xfrm4_dst_ops = *afinfo->dst_ops;
#if IS_ENABLED(CONFIG_IPV6)
- afinfo = xfrm_policy_afinfo[AF_INET6];
+ afinfo = rcu_dereference(xfrm_policy_afinfo[AF_INET6]);
if (afinfo)
net->xfrm.xfrm6_dst_ops = *afinfo->dst_ops;
#endif
- read_unlock_bh(&xfrm_policy_afinfo_lock);
+ rcu_read_unlock_bh();
}
static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
@@ -2514,16 +2517,16 @@ static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
struct xfrm_policy_afinfo *afinfo;
if (unlikely(family >= NPROTO))
return NULL;
- read_lock(&xfrm_policy_afinfo_lock);
- afinfo = xfrm_policy_afinfo[family];
+ rcu_read_lock();
+ afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
if (unlikely(!afinfo))
- read_unlock(&xfrm_policy_afinfo_lock);
+ rcu_read_unlock();
return afinfo;
}
-static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
+static inline void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
{
- read_unlock(&xfrm_policy_afinfo_lock);
+ rcu_read_unlock();
}
static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
--
1.7.4.1
--
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