The patch checks neigh->nud_state before acquiring the writer lock. Note that rt6_probe() is only used in CONFIG_IPV6_ROUTER_PREF.
I also take this chance to re-arrange the code. 40 udpflood processes and a /64 gateway route are used. The gateway has NUD_PERMANENT. Each of them is run for 30s. At the end, the total number of finished sendto(): Before After 55M 95M Signed-off-by: Martin KaFai Lau <ka...@fb.com> Cc: Hannes Frederic Sowa <han...@stressinduktion.org> --- net/ipv6/route.c | 41 ++++++++++++++++++++--------------------- 1 file changed, 20 insertions(+), 21 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 6090969..a6c6b5a 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -544,6 +544,7 @@ static void rt6_probe_deferred(struct work_struct *w) static void rt6_probe(struct rt6_info *rt) { + struct __rt6_probe_work *work; struct neighbour *neigh; /* * Okay, this does not seem to be appropriate @@ -558,34 +559,32 @@ static void rt6_probe(struct rt6_info *rt) rcu_read_lock_bh(); neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway); if (neigh) { - write_lock(&neigh->lock); if (neigh->nud_state & NUD_VALID) goto out; - } - - if (!neigh || - time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) { - struct __rt6_probe_work *work; + work = NULL; + write_lock(&neigh->lock); + if (!(neigh->nud_state & NUD_VALID) && + time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) { + work = kmalloc(sizeof(*work), GFP_ATOMIC); + if (work) { + __neigh_set_probe_once(neigh); + } + } + write_unlock(&neigh->lock); + } else { work = kmalloc(sizeof(*work), GFP_ATOMIC); + } - if (neigh && 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); + } - 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); - } rcu_read_unlock_bh(); } #else -- 1.8.1 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html