ipv4: use skb coalescing in defragmentation
ip_frag_reasm() can use skb_try_coalesce() to build optimized skb,
reducing memory used by them (truesize), and reducing number of cache
line misses and overhead for the consumer.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 695b27f..9dbd3dd 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -545,6 +545,7 @@
int len;
int ihlen;
int err;
+ int sum_truesize;
u8 ecn;
ipq_kill(qp);
@@ -611,19 +612,32 @@
atomic_add(clone->truesize, &qp->q.net->mem);
}
- skb_shinfo(head)->frag_list = head->next;
skb_push(head, head->data - skb_network_header(head));
- for (fp=head->next; fp; fp = fp->next) {
- head->data_len += fp->len;
- head->len += fp->len;
+ sum_truesize = head->truesize;
+ for (fp = head->next; fp;) {
+ bool headstolen;
+ int delta;
+ struct sk_buff *next = fp->next;
+
+ sum_truesize += fp->truesize;
if (head->ip_summed != fp->ip_summed)
head->ip_summed = CHECKSUM_NONE;
else if (head->ip_summed == CHECKSUM_COMPLETE)
head->csum = csum_add(head->csum, fp->csum);
- head->truesize += fp->truesize;
+
+ if (skb_try_coalesce(head, fp, &headstolen, &delta)) {
+ kfree_skb_partial(fp, headstolen);
+ } else {
+ if (!skb_shinfo(head)->frag_list)
+ skb_shinfo(head)->frag_list = fp;
+ head->data_len += fp->len;
+ head->len += fp->len;
+ head->truesize += fp->truesize;
+ }
+ fp = next;
}
- atomic_sub(head->truesize, &qp->q.net->mem);
+ atomic_sub(sum_truesize, &qp->q.net->mem);
head->next = NULL;
head->dev = dev;