net: Add skb_clear_tstamp() to keep the mono delivery_time

Right now, skb->tstamp is reset to 0 whenever the skb is forwarded.

If skb->tstamp has the mono delivery_time, clearing it can hurt
the performance when it finally transmits out to fq@phy-dev.

The earlier patch added a skb->mono_delivery_time bit to
flag the skb->tstamp carrying the mono delivery_time.

This patch adds skb_clear_tstamp() helper which keeps
the mono delivery_time and clears everything else.

The delivery_time clearing will be postponed until the stack knows the
skb will be delivered locally.  It will be done in a latter patch.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index d05f86f..720394c 100644 (file)
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -74,7 +74,7 @@ static netdev_tx_t loopback_xmit(struct sk_buff *skb,
        skb_tx_timestamp(skb);
 
        /* do not fool net_timestamp_check() with various clock bases */
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
 
        skb_orphan(skb);
 

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 803ffa6..27a2892 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3996,6 +3996,14 @@ static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt,
        skb->mono_delivery_time = 0;
 }
 
+static inline void skb_clear_tstamp(struct sk_buff *skb)
+{
+       if (skb->mono_delivery_time)
+               return;
+
+       skb->tstamp = 0;
+}
+
 static inline u8 skb_metadata_len(const struct sk_buff *skb)
 {
        return skb_shinfo(skb)->meta_len;
@@ -4852,7 +4860,7 @@ static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress)
 #ifdef CONFIG_NET_REDIRECT
        skb->from_ingress = from_ingress;
        if (skb->from_ingress)
-               skb->tstamp = 0;
+               skb_clear_tstamp(skb);
 #endif
 }
 

diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index ec64665..02bb620 100644 (file)
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -62,7 +62,7 @@ EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
 
 int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
        return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING,
                       net, sk, skb, NULL, skb->dev,
                       br_dev_queue_push_xmit);

diff --git a/net/core/filter.c b/net/core/filter.c
index 65869fd..cfcf9b4 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2107,7 +2107,7 @@ static inline int __bpf_tx_skb(struct net_device *dev, struct sk_buff *skb)
        }
 
        skb->dev = dev;
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
 
        dev_xmit_recursion_inc();
        ret = dev_queue_xmit(skb);
@@ -2176,7 +2176,7 @@ static int bpf_out_neigh_v6(struct net *net, struct sk_buff *skb,
        }
 
        skb->dev = dev;
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
 
        if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
                skb = skb_expand_head(skb, hh_len);
@@ -2274,7 +2274,7 @@ static int bpf_out_neigh_v4(struct net *net, struct sk_buff *skb,
        }
 
        skb->dev = dev;
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
 
        if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
                skb = skb_expand_head(skb, hh_len);

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index b32c5d7..9abb002 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -5381,7 +5381,7 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet)
 
        ipvs_reset(skb);
        skb->mark = 0;
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
 }
 EXPORT_SYMBOL_GPL(skb_scrub_packet);
 

diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index 00ec819..92ba335 100644 (file)
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -79,7 +79,7 @@ static int ip_forward_finish(struct net *net, struct sock *sk, struct sk_buff *s
        if (unlikely(opt->optlen))
                ip_forward_options(skb);
 
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
        return dst_output(net, sk, skb);
 }
 

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index dad4e3d..50db9b2 100644 (file)
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -440,7 +440,7 @@ static inline int ip6_forward_finish(struct net *net, struct sock *sk,
        }
 #endif
 
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
        return dst_output(net, sk, skb);
 }
 

diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index d2e5a8f..0291713 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -610,7 +610,7 @@ static inline int ip_vs_tunnel_xmit_prepare(struct sk_buff *skb,
                nf_reset_ct(skb);
                skb_forward_csum(skb);
                if (skb->dev)
-                       skb->tstamp = 0;
+                       skb_clear_tstamp(skb);
        }
        return ret;
 }
@@ -652,7 +652,7 @@ static inline int ip_vs_nat_send_or_cont(int pf, struct sk_buff *skb,
        if (!local) {
                skb_forward_csum(skb);
                if (skb->dev)
-                       skb->tstamp = 0;
+                       skb_clear_tstamp(skb);
                NF_HOOK(pf, NF_INET_LOCAL_OUT, cp->ipvs->net, NULL, skb,
                        NULL, skb_dst(skb)->dev, dst_output);
        } else
@@ -674,7 +674,7 @@ static inline int ip_vs_send_or_cont(int pf, struct sk_buff *skb,
                ip_vs_drop_early_demux_sk(skb);
                skb_forward_csum(skb);
                if (skb->dev)
-                       skb->tstamp = 0;
+                       skb_clear_tstamp(skb);
                NF_HOOK(pf, NF_INET_LOCAL_OUT, cp->ipvs->net, NULL, skb,
                        NULL, skb_dst(skb)->dev, dst_output);
        } else

diff --git a/net/netfilter/nf_dup_netdev.c b/net/netfilter/nf_dup_netdev.c
index a579e59..7873bd1 100644 (file)
--- a/net/netfilter/nf_dup_netdev.c
+++ b/net/netfilter/nf_dup_netdev.c
@@ -19,7 +19,7 @@ static void nf_do_netdev_egress(struct sk_buff *skb, struct net_device *dev)
                skb_push(skb, skb->mac_len);
 
        skb->dev = dev;
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
        dev_queue_xmit(skb);
 }
 

diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index 889cf88..f1d3871 100644 (file)
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -376,7 +376,7 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
        nf_flow_nat_ip(flow, skb, thoff, dir, iph);
 
        ip_decrease_ttl(iph);
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
 
        if (flow_table->flags & NF_FLOWTABLE_COUNTER)
                nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
@@ -611,7 +611,7 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
        nf_flow_nat_ipv6(flow, skb, dir, ip6h);
 
        ip6h->hop_limit--;
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
 
        if (flow_table->flags & NF_FLOWTABLE_COUNTER)
                nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);

diff --git a/net/netfilter/nft_fwd_netdev.c b/net/netfilter/nft_fwd_netdev.c
index 619e394..08e7a28 100644 (file)
--- a/net/netfilter/nft_fwd_netdev.c
+++ b/net/netfilter/nft_fwd_netdev.c
@@ -145,7 +145,7 @@ static void nft_fwd_neigh_eval(const struct nft_expr *expr,
                return;
 
        skb->dev = dev;
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
        neigh_xmit(neigh_table, dev, addr, skb);
 out:
        regs->verdict.code = verdict;

diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index cf2ce58..82a74f9 100644 (file)
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c
@@ -507,7 +507,7 @@ void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto)
        }
 
        skb->dev = vport->dev;
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
        vport->ops->send(skb);
        return;
 

diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c
index 57448fc..4991e99 100644 (file)
--- a/net/xfrm/xfrm_interface.c
+++ b/net/xfrm/xfrm_interface.c
@@ -190,7 +190,7 @@ static void xfrmi_dev_uninit(struct net_device *dev)
 
 static void xfrmi_scrub_packet(struct sk_buff *skb, bool xnet)
 {
-       skb->tstamp = 0;
+       skb_clear_tstamp(skb);
        skb->pkt_type = PACKET_HOST;
        skb->skb_iif = 0;
        skb->ignore_df = 0;