Re: [Bugme-new] [Bug 11316] New: severe performance regression for iptables nat routing
From: David Miller <davem@davemloft.net>
Date: 2008-08-15 21:54:35
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2008-08-15 · Re: [Bugme-new] [Bug 11316] New: severe performance regression for iptables nat routing · David Miller <davem@davemloft.net>
- 2008-08-15 · Re: [Bugme-new] [Bug 11316] New: severe performance regression for iptables nat routing · Herbert Xu <herbert@gondor.apana.org.au>
- 2008-08-15 · Re: [Bugme-new] [Bug 11316] New: severe performance regression for iptables nat routing · Alex Williamson <hidden>
- 2008-08-15 · Re: [Bugme-new] [Bug 11316] New: severe performance regression for iptables nat routing · Herbert Xu <herbert@gondor.apana.org.au>
- 2008-08-15 · Re: [Bugme-new] [Bug 11316] New: severe performance regression for iptables nat routing · Herbert Xu <herbert@gondor.apana.org.au>
From: Herbert Xu <herbert@gondor.apana.org.au> Date: Fri, 15 Aug 2008 20:32:35 +1000
loopback: Enable TSO This patch enables TSO since the loopback device is naturally capable of handling packets of any size. This also means that we won't enable GSO on lo which is good until GSO is fixed to preserve netfilter state as netfilter treats loopback packets in a special way. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Meanwhile I applied this and I took the liberty of applying the following right afterwards: loopback: Remove rest of LOOPBACK_TSO code. It hasn't been enabled for a long time and the generic GSO engine is better documentation of what is expected of a device implementing TSO. Signed-off-by: David S. Miller <davem@davemloft.net> --- drivers/net/loopback.c | 62 ------------------------------------------------ 1 files changed, 0 insertions(+), 62 deletions(-)
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 46e87cc..489d53b 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c@@ -64,68 +64,6 @@ struct pcpu_lstats { unsigned long bytes; }; -/* KISS: just allocate small chunks and copy bits. - * - * So, in fact, this is documentation, explaining what we expect - * of largesending device modulo TCP checksum, which is ignored for loopback. - */ - -#ifdef LOOPBACK_TSO -static void emulate_large_send_offload(struct sk_buff *skb) -{ - struct iphdr *iph = ip_hdr(skb); - struct tcphdr *th = (struct tcphdr *)(skb_network_header(skb) + - (iph->ihl * 4)); - unsigned int doffset = (iph->ihl + th->doff) * 4; - unsigned int mtu = skb_shinfo(skb)->gso_size + doffset; - unsigned int offset = 0; - u32 seq = ntohl(th->seq); - u16 id = ntohs(iph->id); - - while (offset + doffset < skb->len) { - unsigned int frag_size = min(mtu, skb->len - offset) - doffset; - struct sk_buff *nskb = alloc_skb(mtu + 32, GFP_ATOMIC); - - if (!nskb) - break; - skb_reserve(nskb, 32); - skb_set_mac_header(nskb, -ETH_HLEN); - skb_reset_network_header(nskb); - iph = ip_hdr(nskb); - skb_copy_to_linear_data(nskb, skb_network_header(skb), - doffset); - if (skb_copy_bits(skb, - doffset + offset, - nskb->data + doffset, - frag_size)) - BUG(); - skb_put(nskb, doffset + frag_size); - nskb->ip_summed = CHECKSUM_UNNECESSARY; - nskb->dev = skb->dev; - nskb->priority = skb->priority; - nskb->protocol = skb->protocol; - nskb->dst = dst_clone(skb->dst); - memcpy(nskb->cb, skb->cb, sizeof(skb->cb)); - nskb->pkt_type = skb->pkt_type; - - th = (struct tcphdr *)(skb_network_header(nskb) + iph->ihl * 4); - iph->tot_len = htons(frag_size + doffset); - iph->id = htons(id); - iph->check = 0; - iph->check = ip_fast_csum((unsigned char *) iph, iph->ihl); - th->seq = htonl(seq); - if (offset + doffset + frag_size < skb->len) - th->fin = th->psh = 0; - netif_rx(nskb); - offset += frag_size; - seq += frag_size; - id++; - } - - dev_kfree_skb(skb); -} -#endif /* LOOPBACK_TSO */ - /* * The higher levels take care of making this non-reentrant (it's * called with bh's disabled).
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1.5.6.5.GIT