From 3ef0eb0db4bf92c6d2510fe5c4dc51852746f206 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Mon, 28 Jan 2013 23:45:51 +0000 Subject: [PATCH] net: frag, move LRU list maintenance outside of rwlock Updating the fragmentation queues LRU (Least-Recently-Used) list, required taking the hash writer lock. However, the LRU list isn't tied to the hash at all, so we can use a separate lock for it. Original-idea-by: Florian Westphal Signed-off-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller --- include/net/inet_frag.h | 22 ++++++++++++++++++++++ net/ipv4/inet_fragment.c | 12 +++++++----- net/ipv4/ip_fragment.c | 4 +--- net/ipv6/netfilter/nf_conntrack_reasm.c | 5 ++--- net/ipv6/reassembly.c | 4 +--- 5 files changed, 33 insertions(+), 14 deletions(-) diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h index e0eec74..3f237db 100644 --- a/include/net/inet_frag.h +++ b/include/net/inet_frag.h @@ -6,6 +6,7 @@ struct netns_frags { int nqueues; struct list_head lru_list; + spinlock_t lru_lock; /* The percpu_counter "mem" need to be cacheline aligned. * mem.count must not share cacheline with other writers @@ -116,4 +117,25 @@ static inline int sum_frag_mem_limit(struct netns_frags *nf) return percpu_counter_sum_positive(&nf->mem); } +static inline void inet_frag_lru_move(struct inet_frag_queue *q) +{ + spin_lock(&q->net->lru_lock); + list_move_tail(&q->lru_list, &q->net->lru_list); + spin_unlock(&q->net->lru_lock); +} + +static inline void inet_frag_lru_del(struct inet_frag_queue *q) +{ + spin_lock(&q->net->lru_lock); + list_del(&q->lru_list); + spin_unlock(&q->net->lru_lock); +} + +static inline void inet_frag_lru_add(struct netns_frags *nf, + struct inet_frag_queue *q) +{ + spin_lock(&nf->lru_lock); + list_add_tail(&q->lru_list, &nf->lru_list); + spin_unlock(&nf->lru_lock); +} #endif diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c index b825205..2e453bd 100644 --- a/net/ipv4/inet_fragment.c +++ b/net/ipv4/inet_fragment.c @@ -75,6 +75,7 @@ void inet_frags_init_net(struct netns_frags *nf) nf->nqueues = 0; init_frag_mem_limit(nf); INIT_LIST_HEAD(&nf->lru_list); + spin_lock_init(&nf->lru_lock); } EXPORT_SYMBOL(inet_frags_init_net); @@ -100,9 +101,9 @@ static inline void fq_unlink(struct inet_frag_queue *fq, struct inet_frags *f) { write_lock(&f->lock); hlist_del(&fq->list); - list_del(&fq->lru_list); fq->net->nqueues--; write_unlock(&f->lock); + inet_frag_lru_del(fq); } void inet_frag_kill(struct inet_frag_queue *fq, struct inet_frags *f) @@ -170,16 +171,17 @@ int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f, bool force) work = frag_mem_limit(nf) - nf->low_thresh; while (work > 0) { - read_lock(&f->lock); + spin_lock(&nf->lru_lock); + if (list_empty(&nf->lru_list)) { - read_unlock(&f->lock); + spin_unlock(&nf->lru_lock); break; } q = list_first_entry(&nf->lru_list, struct inet_frag_queue, lru_list); atomic_inc(&q->refcnt); - read_unlock(&f->lock); + spin_unlock(&nf->lru_lock); spin_lock(&q->lock); if (!(q->last_in & INET_FRAG_COMPLETE)) @@ -233,9 +235,9 @@ static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf, atomic_inc(&qp->refcnt); hlist_add_head(&qp->list, &f->hash[hash]); - list_add_tail(&qp->lru_list, &nf->lru_list); nf->nqueues++; write_unlock(&f->lock); + inet_frag_lru_add(nf, qp); return qp; } diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index 927fe58..1211613 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -529,9 +529,7 @@ found: qp->q.meat == qp->q.len) return ip_frag_reasm(qp, prev, dev); - write_lock(&ip4_frags.lock); - list_move_tail(&qp->q.lru_list, &qp->q.net->lru_list); - write_unlock(&ip4_frags.lock); + inet_frag_lru_move(&qp->q); return -EINPROGRESS; err: diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index 07ef294..c674f15 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -328,9 +328,8 @@ found: fq->nhoffset = nhoff; fq->q.last_in |= INET_FRAG_FIRST_IN; } - write_lock(&nf_frags.lock); - list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list); - write_unlock(&nf_frags.lock); + + inet_frag_lru_move(&fq->q); return 0; discard_fq: diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 18cb8de..bab2c27 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -341,9 +341,7 @@ found: fq->q.meat == fq->q.len) return ip6_frag_reasm(fq, prev, dev); - write_lock(&ip6_frags.lock); - list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list); - write_unlock(&ip6_frags.lock); + inet_frag_lru_move(&fq->q); return -1; discard_fq: -- 2.7.4