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Merge branch 'rt6_probe_write_lock' 

Martin KaFai Lau says:

====================
ipv6: Avoid rt6_probe() taking writer lock in the fast path

v1 -> v2:
1. Separate the code re-arrangement into another patch
2. Fix style
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2015-07-27 01:08:26 -07:00
parent 205845a347 8d6c31bf57
commit 70d2db7b21
1 changed files with 22 additions and 22 deletions
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44
net/ipv6/route.c
View File

@ -545,6 +545,7 @@ static void rt6_probe_deferred(struct work_struct *w)
static void rt6_probe(struct rt6_info *rt) static void rt6_probe(struct rt6_info *rt)
{ {
struct __rt6_probe_work *work;
struct neighbour *neigh; struct neighbour *neigh;
/* /*
* Okay, this does not seem to be appropriate * Okay, this does not seem to be appropriate
@ -559,34 +560,33 @@ static void rt6_probe(struct rt6_info *rt)
rcu_read_lock_bh(); rcu_read_lock_bh();
neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway); neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
if (neigh) { if (neigh) {
write_lock(&neigh->lock);
if (neigh->nud_state & NUD_VALID) if (neigh->nud_state & NUD_VALID)
goto out; goto out;
}
if (!neigh || work = NULL;
time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) { write_lock(&neigh->lock);
struct __rt6_probe_work *work; if (!(neigh->nud_state & NUD_VALID) &&
time_after(jiffies,
work = kmalloc(sizeof(*work), GFP_ATOMIC); neigh->updated +
rt->rt6i_idev->cnf.rtr_probe_interval)) {
if (neigh && work) work = kmalloc(sizeof(*work), GFP_ATOMIC);
__neigh_set_probe_once(neigh); if (work)
__neigh_set_probe_once(neigh);
if (neigh)
write_unlock(&neigh->lock);
if (work) {
INIT_WORK(&work->work, rt6_probe_deferred);
work->target = rt->rt6i_gateway;
dev_hold(rt->dst.dev);
work->dev = rt->dst.dev;
schedule_work(&work->work);
} }
} else {
out:
write_unlock(&neigh->lock); write_unlock(&neigh->lock);
} else {
work = kmalloc(sizeof(*work), GFP_ATOMIC);
} }
if (work) {
INIT_WORK(&work->work, rt6_probe_deferred);
work->target = rt->rt6i_gateway;
dev_hold(rt->dst.dev);
work->dev = rt->dst.dev;
schedule_work(&work->work);
}
out:
rcu_read_unlock_bh(); rcu_read_unlock_bh();
} }
#else #else