commit 1b5ab0def4f6e42e8b8097c3b11d2e8d96baafec
author Jesper Dangaard Brouer <brouer@redhat.com> Wed Mar 27 05:55:56 2013 +0000
committer David S. Miller <davem@davemloft.net> Wed Mar 27 12:48:33 2013 -0400
tree 7cdce8ba8eda1451847fead45108f4de39d5cec5
parent 68399ac37e571c2d695ea3b08aa82235874b5158

net: use the frag lru_lock to protect netns_frags.nqueues update

Move the protection of netns_frags.nqueues updates under the LRU_lock,
instead of the write lock.  As they are located on the same cacheline,
and this is also needed when transitioning to use per hash bucket locking.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/inet_frag.h

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index 64b4e7d..7cac9c5 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -143,6 +143,7 @@
 {
 	spin_lock(&q->net->lru_lock);
 	list_del(&q->lru_list);
+	q->net->nqueues--;
 	spin_unlock(&q->net->lru_lock);
 }
 
@@ -151,6 +152,7 @@
 {
 	spin_lock(&nf->lru_lock);
 	list_add_tail(&q->lru_list, &nf->lru_list);
+	q->net->nqueues++;
 	spin_unlock(&nf->lru_lock);
 }
 

net/ipv4/inet_fragment.c

diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 8ba548a..1206ca6 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -124,7 +124,6 @@
 {
 	write_lock(&f->lock);
 	hlist_del(&fq->list);
-	fq->net->nqueues--;
 	write_unlock(&f->lock);
 	inet_frag_lru_del(fq);
 }
@@ -260,7 +259,6 @@
 
 	atomic_inc(&qp->refcnt);
 	hlist_add_head(&qp->list, &f->hash[hash]);
-	nf->nqueues++;
 	write_unlock(&f->lock);
 	inet_frag_lru_add(nf, qp);
 	return qp;