diff options
| author | David S. Miller <davem@davemloft.net> | 2015-07-27 01:08:26 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-07-27 01:08:26 -0700 |
| commit | 70d2db7b21684bb2b808e78fbab8e594dd7e50ce (patch) | |
| tree | f1ff57e6fb696f41ab3e48c4b07fbcc539d52a33 | |
| parent | 205845a34763432040496908c8f52f1f97e5ee62 (diff) | |
| parent | 8d6c31bf574177c8de48dd1387d96e1ec3a8b8bc (diff) | |
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>
| -rw-r--r-- | net/ipv6/route.c | 42 |
1 files changed, 21 insertions, 21 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index c9b2b9fe83fc..54fccf0d705d 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -545,6 +545,7 @@ 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 @@ -559,34 +560,33 @@ 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 |