| Message ID | 1437757063-1186401-2-git-send-email-kafai@fb.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
Martin KaFai Lau wrote: > It is a prep work for the next patch to remove write_lock > from rt6_probe(). > > 1. Reduce the number of if(neigh) check. From 4 to 1. > 2. Bring the write_(un)lock() closer to the operations that the > lock is protecting. > > Hopefully, the above make rt6_probe() more readable. > > Signed-off-by: Martin KaFai Lau <kafai@fb.com> > Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> > Cc: Julian Anastasov <ja@ssi.bg> > Cc: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com> Acked-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com> --yoshfuji > --- > net/ipv6/route.c | 44 ++++++++++++++++++++------------------------ > 1 file changed, 20 insertions(+), 24 deletions(-) > > diff --git a/net/ipv6/route.c b/net/ipv6/route.c > index 7f2214f..6d503db 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 +560,29 @@ 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) { > + work = NULL; > 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 = 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 (!(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); > } > - } else { > -out: > 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); > } > + > rcu_read_unlock_bh(); > } > #else >
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 7f2214f..6d503db 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 +560,29 @@ 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) { + work = NULL; 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 = 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 (!(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); } - } else { -out: 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); } + rcu_read_unlock_bh(); } #else
It is a prep work for the next patch to remove write_lock from rt6_probe(). 1. Reduce the number of if(neigh) check. From 4 to 1. 2. Bring the write_(un)lock() closer to the operations that the lock is protecting. Hopefully, the above make rt6_probe() more readable. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Julian Anastasov <ja@ssi.bg> Cc: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com> --- net/ipv6/route.c | 44 ++++++++++++++++++++------------------------ 1 file changed, 20 insertions(+), 24 deletions(-)