[PATCH net-next 11/12] tcp: Namespace-ify sysctl_tcp_pacing_ss_ratio

[Eric Dumazet]

Also remove an obsolete comment about TCP pacing.

Signed-off-by: Eric Dumazet <eduma...@google.com>
---
 include/net/netns/ipv4.h   |  1 +
 include/net/tcp.h          |  1 -
 net/ipv4/sysctl_net_ipv4.c | 18 +++++++++---------
 net/ipv4/tcp_input.c       |  9 +--------
 net/ipv4/tcp_ipv4.c        |  1 +
 5 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 
e52c2124b32e799f32943621cc0cc55dc7d8413d..eb2dcf1cbe61bf392e1c186e6fd1a11b82d8bad2
 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -152,6 +152,7 @@ struct netns_ipv4 {
        int sysctl_tcp_min_rtt_wlen;
        int sysctl_tcp_autocorking;
        int sysctl_tcp_invalid_ratelimit;
+       int sysctl_tcp_pacing_ss_ratio;
        struct inet_timewait_death_row tcp_death_row;
        int sysctl_max_syn_backlog;
        int sysctl_tcp_fastopen;
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 
5869a822ecb1b8f350cb393b4b43343ccf206eb5..2a5f8261ca03b76061dfbe85bbcf0fa15e5f8b40
 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -250,7 +250,6 @@ extern int sysctl_tcp_rmem[3];
 
 #define TCP_RACK_LOSS_DETECTION  0x1 /* Use RACK to detect losses */
 
-extern int sysctl_tcp_pacing_ss_ratio;
 extern int sysctl_tcp_pacing_ca_ratio;
 
 extern atomic_long_t tcp_memory_allocated;
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 
6a9349c27f00b1a665b969fe0291d195ec473e3e..7f0dba852d471a6e78d508d0b87966e26d4ca621
 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -492,15 +492,6 @@ static struct ctl_table ipv4_table[] = {
                .mode           = 0644,
                .proc_handler   = proc_allowed_congestion_control,
        },
-       {
-               .procname       = "tcp_pacing_ss_ratio",
-               .data           = &sysctl_tcp_pacing_ss_ratio,
-               .maxlen         = sizeof(int),
-               .mode           = 0644,
-               .proc_handler   = proc_dointvec_minmax,
-               .extra1         = &zero,
-               .extra2         = &thousand,
-       },
        {
                .procname       = "tcp_pacing_ca_ratio",
                .data           = &sysctl_tcp_pacing_ca_ratio,
@@ -1145,6 +1136,15 @@ static struct ctl_table ipv4_net_table[] = {
                .mode           = 0644,
                .proc_handler   = proc_dointvec_ms_jiffies,
        },
+       {
+               .procname       = "tcp_pacing_ss_ratio",
+               .data           = &init_net.ipv4.sysctl_tcp_pacing_ss_ratio,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &zero,
+               .extra2         = &thousand,
+       },
        { }
 };
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 
db4d458d0205027681f96498019a5fd0bb0303b8..29539d39e61a0b99267e6c9b8f63b8acf6ae6200
 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -767,13 +767,6 @@ static void tcp_rtt_estimator(struct sock *sk, long 
mrtt_us)
        tp->srtt_us = max(1U, srtt);
 }
 
-/* Set the sk_pacing_rate to allow proper sizing of TSO packets.
- * Note: TCP stack does not yet implement pacing.
- * FQ packet scheduler can be used to implement cheap but effective
- * TCP pacing, to smooth the burst on large writes when packets
- * in flight is significantly lower than cwnd (or rwin)
- */
-int sysctl_tcp_pacing_ss_ratio __read_mostly = 200;
 int sysctl_tcp_pacing_ca_ratio __read_mostly = 120;
 
 static void tcp_update_pacing_rate(struct sock *sk)
@@ -793,7 +786,7 @@ static void tcp_update_pacing_rate(struct sock *sk)
         *       end of slow start and should slow down.
         */
        if (tp->snd_cwnd < tp->snd_ssthresh / 2)
-               rate *= sysctl_tcp_pacing_ss_ratio;
+               rate *= sock_net(sk)->ipv4.sysctl_tcp_pacing_ss_ratio;
        else
                rate *= sysctl_tcp_pacing_ca_ratio;
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 
6617aae18ba2e2ad23663708a39311b0e987522d..1d8fc663af51f4d248de73ee30e28db44ffc940a
 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2507,6 +2507,7 @@ static int __net_init tcp_sk_init(struct net *net)
        net->ipv4.sysctl_tcp_min_rtt_wlen = 300;
        net->ipv4.sysctl_tcp_autocorking = 1;
        net->ipv4.sysctl_tcp_invalid_ratelimit = HZ/2;
+       net->ipv4.sysctl_tcp_pacing_ss_ratio = 200;
 
        net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE;
        spin_lock_init(&net->ipv4.tcp_fastopen_ctx_lock);
-- 
2.15.0.rc2.357.g7e34df9404-goog