netfilter: defrag: remove one redundant atomic ops
Instead of doing one atomic operation per frag, we can factorize them.
Reported from Eric Dumazet.
Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 6fb8901..bc5b86d 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -442,7 +442,6 @@
skb_shinfo(head)->frag_list = head->next;
skb_reset_transport_header(head);
skb_push(head, head->data - skb_network_header(head));
- atomic_sub(head->truesize, &nf_init_frags.mem);
for (fp=head->next; fp; fp = fp->next) {
head->data_len += fp->len;
@@ -452,8 +451,8 @@
else if (head->ip_summed == CHECKSUM_COMPLETE)
head->csum = csum_add(head->csum, fp->csum);
head->truesize += fp->truesize;
- atomic_sub(fp->truesize, &nf_init_frags.mem);
}
+ atomic_sub(head->truesize, &nf_init_frags.mem);
head->next = NULL;
head->dev = dev;