From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH net-next 3/3] ipv6: use skb coalescing in reassembly Date: Sat, 19 May 2012 15:02:35 +0200 Message-ID: <1337432555.7029.196.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev , Alexander Duyck To: David Miller Return-path: Received: from mail-we0-f174.google.com ([74.125.82.174]:49776 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758646Ab2ESNCi (ORCPT ); Sat, 19 May 2012 09:02:38 -0400 Received: by weyu7 with SMTP id u7so2320908wey.19 for ; Sat, 19 May 2012 06:02:37 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet ip6_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 Cc: Alexander Duyck --- net/ipv6/reassembly.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 5d32dfa..4ff9af6 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -415,6 +415,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, struct sk_buff *fp, *head = fq->q.fragments; int payload_len; unsigned int nhoff; + int sum_truesize; fq_kill(fq); @@ -484,20 +485,33 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, head->mac_header += sizeof(struct frag_hdr); head->network_header += sizeof(struct frag_hdr); - skb_shinfo(head)->frag_list = head->next; skb_reset_transport_header(head); 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, &fq->q.net->mem); + atomic_sub(sum_truesize, &fq->q.net->mem); head->next = NULL; head->dev = dev;