net: frag helper functions for mem limit tracking

This change is primarily a preparation to ease the extension of memory
limit tracking.

The change does reduce the number atomic operation, during freeing of
a frag queue.  This does introduce a some performance improvement, as
these atomic operations are at the core of the performance problems
seen on NUMA systems.

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

1 files changed, 12 insertions, 13 deletions

diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 4750d2b74d79..e348c849c5a3 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -73,7 +73,7 @@ EXPORT_SYMBOL(inet_frags_init);
 void inet_frags_init_net(struct netns_frags *nf)
 {
         nf->nqueues = 0;
-        atomic_set(&nf->mem, 0);
+        init_frag_mem_limit(nf);
         INIT_LIST_HEAD(&nf->lru_list);
 }
 EXPORT_SYMBOL(inet_frags_init_net);
@@ -117,12 +117,8 @@ void inet_frag_kill(struct inet_frag_queue *fq, struct inet_frags *f)
 EXPORT_SYMBOL(inet_frag_kill);
 
 static inline void frag_kfree_skb(struct netns_frags *nf, struct inet_frags *f,
-                struct sk_buff *skb, int *work)
+                struct sk_buff *skb)
 {
-        if (work)
-                *work -= skb->truesize;
-
-        atomic_sub(skb->truesize, &nf->mem);
         if (f->skb_free)
                 f->skb_free(skb);
         kfree_skb(skb);
@@ -133,6 +129,7 @@ void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f,
 {
         struct sk_buff *fp;
         struct netns_frags *nf;
+        unsigned int sum, sum_truesize = 0;
 
         WARN_ON(!(q->last_in & INET_FRAG_COMPLETE));
         WARN_ON(del_timer(&q->timer) != 0);
@@ -143,13 +140,14 @@ void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f,
         while (fp) {
                 struct sk_buff *xp = fp->next;
 
-                frag_kfree_skb(nf, f, fp, work);
+                sum_truesize += fp->truesize;
+                frag_kfree_skb(nf, f, fp);
                 fp = xp;
         }
-
+        sum = sum_truesize + f->qsize;
         if (work)
-                *work -= f->qsize;
-        atomic_sub(f->qsize, &nf->mem);
+                *work -= sum;
+        sub_frag_mem_limit(q, sum);
 
         if (f->destructor)
                 f->destructor(q);
@@ -164,11 +162,11 @@ int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f, bool force)
         int work, evicted = 0;
 
         if (!force) {
-                if (atomic_read(&nf->mem) <= nf->high_thresh)
+                if (frag_mem_limit(nf) <= nf->high_thresh)
                         return 0;
         }
 
-        work = atomic_read(&nf->mem) - nf->low_thresh;
+        work = frag_mem_limit(nf) - nf->low_thresh;
         while (work > 0) {
                 read_lock(&f->lock);
                 if (list_empty(&nf->lru_list)) {
@@ -250,7 +248,8 @@ static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
 
         q->net = nf;
         f->constructor(q, arg);
-        atomic_add(f->qsize, &nf->mem);
+        add_frag_mem_limit(q, f->qsize);
+
         setup_timer(&q->timer, f->frag_expire, (unsigned long)q);
         spin_lock_init(&q->lock);
         atomic_set(&q->refcnt, 1);