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tcp: Namespace-ify sysctl_tcp_rmem and sysctl_tcp_wmem
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Note that when a new netns is created, it inherits its
sysctl_tcp_rmem and sysctl_tcp_wmem from initial netns.

This change is needed so that we can refine TCP rcvbuf autotuning,
to take RTT into consideration.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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@davem330
Eric Dumazet authored and davem330 committed Nov 10, 2017
1 parent a3dcaf1 commit 356d183
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Showing 8 changed files with 47 additions and 43 deletions.
2 changes: 2 additions & 0 deletions include/net/netns/ipv4.h
View file
Expand Up @@ -155,6 +155,8 @@ struct netns_ipv4 {
int sysctl_tcp_invalid_ratelimit;
int sysctl_tcp_pacing_ss_ratio;
int sysctl_tcp_pacing_ca_ratio;
int sysctl_tcp_wmem[3];
int sysctl_tcp_rmem[3];
struct inet_timewait_death_row tcp_death_row;
int sysctl_max_syn_backlog;
int sysctl_tcp_fastopen;
Expand Down
2 changes: 0 additions & 2 deletions include/net/tcp.h
View file
Expand Up @@ -242,8 +242,6 @@ void tcp_time_wait(struct sock *sk, int state, int timeo);
/* sysctl variables for tcp */
extern int sysctl_tcp_max_orphans;
extern long sysctl_tcp_mem[3];
extern int sysctl_tcp_wmem[3];
extern int sysctl_tcp_rmem[3];

#define TCP_RACK_LOSS_DETECTION 0x1 /* Use RACK to detect losses */
#define TCP_RACK_STATIC_REO_WND 0x2 /* Use static RACK reo wnd */
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32 changes: 16 additions & 16 deletions net/ipv4/sysctl_net_ipv4.c
View file
Expand Up @@ -440,22 +440,6 @@ static struct ctl_table ipv4_table[] = {
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
},
{
.procname = "tcp_wmem",
.data = &sysctl_tcp_wmem,
.maxlen = sizeof(sysctl_tcp_wmem),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &one,
},
{
.procname = "tcp_rmem",
.data = &sysctl_tcp_rmem,
.maxlen = sizeof(sysctl_tcp_rmem),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &one,
},
{
.procname = "tcp_low_latency",
.data = &sysctl_tcp_low_latency,
Expand Down Expand Up @@ -1164,6 +1148,22 @@ static struct ctl_table ipv4_net_table[] = {
.extra1 = &zero,
.extra2 = &thousand,
},
{
.procname = "tcp_wmem",
.data = &init_net.ipv4.sysctl_tcp_wmem,
.maxlen = sizeof(init_net.ipv4.sysctl_tcp_wmem),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &one,
},
{
.procname = "tcp_rmem",
.data = &init_net.ipv4.sysctl_tcp_rmem,
.maxlen = sizeof(init_net.ipv4.sysctl_tcp_rmem),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &one,
},
{ }
};

Expand Down
21 changes: 8 additions & 13 deletions net/ipv4/tcp.c
View file
Expand Up @@ -289,12 +289,7 @@ struct percpu_counter tcp_orphan_count;
EXPORT_SYMBOL_GPL(tcp_orphan_count);

long sysctl_tcp_mem[3] __read_mostly;
int sysctl_tcp_wmem[3] __read_mostly;
int sysctl_tcp_rmem[3] __read_mostly;

EXPORT_SYMBOL(sysctl_tcp_mem);
EXPORT_SYMBOL(sysctl_tcp_rmem);
EXPORT_SYMBOL(sysctl_tcp_wmem);

atomic_long_t tcp_memory_allocated; /* Current allocated memory. */
EXPORT_SYMBOL(tcp_memory_allocated);
Expand Down Expand Up @@ -456,8 +451,8 @@ void tcp_init_sock(struct sock *sk)

icsk->icsk_sync_mss = tcp_sync_mss;

sk->sk_sndbuf = sysctl_tcp_wmem[1];
sk->sk_rcvbuf = sysctl_tcp_rmem[1];
sk->sk_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[1];
sk->sk_rcvbuf = sock_net(sk)->ipv4.sysctl_tcp_rmem[1];

sk_sockets_allocated_inc(sk);
}
Expand Down Expand Up @@ -3636,13 +3631,13 @@ void __init tcp_init(void)
max_wshare = min(4UL*1024*1024, limit);
max_rshare = min(6UL*1024*1024, limit);

sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
sysctl_tcp_wmem[1] = 16*1024;
sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
init_net.ipv4.sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
init_net.ipv4.sysctl_tcp_wmem[1] = 16*1024;
init_net.ipv4.sysctl_tcp_wmem[2] = max(64*1024, max_wshare);

sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
sysctl_tcp_rmem[1] = 87380;
sysctl_tcp_rmem[2] = max(87380, max_rshare);
init_net.ipv4.sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
init_net.ipv4.sysctl_tcp_rmem[1] = 87380;
init_net.ipv4.sysctl_tcp_rmem[2] = max(87380, max_rshare);

pr_info("Hash tables configured (established %u bind %u)\n",
tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
Expand Down
14 changes: 8 additions & 6 deletions net/ipv4/tcp_input.c
View file
Expand Up @@ -320,7 +320,7 @@ static void tcp_sndbuf_expand(struct sock *sk)
sndmem *= nr_segs * per_mss;

if (sk->sk_sndbuf < sndmem)
sk->sk_sndbuf = min(sndmem, sysctl_tcp_wmem[2]);
sk->sk_sndbuf = min(sndmem, sock_net(sk)->ipv4.sysctl_tcp_wmem[2]);
}

/* 2. Tuning advertised window (window_clamp, rcv_ssthresh)
Expand Down Expand Up @@ -354,7 +354,7 @@ static int __tcp_grow_window(const struct sock *sk, const struct sk_buff *skb)
struct tcp_sock *tp = tcp_sk(sk);
/* Optimize this! */
int truesize = tcp_win_from_space(sk, skb->truesize) >> 1;
int window = tcp_win_from_space(sk, sysctl_tcp_rmem[2]) >> 1;
int window = tcp_win_from_space(sk, sock_net(sk)->ipv4.sysctl_tcp_rmem[2]) >> 1;

while (tp->rcv_ssthresh <= window) {
if (truesize <= skb->len)
Expand Down Expand Up @@ -409,7 +409,7 @@ static void tcp_fixup_rcvbuf(struct sock *sk)
rcvmem <<= 2;

if (sk->sk_rcvbuf < rcvmem)
sk->sk_rcvbuf = min(rcvmem, sysctl_tcp_rmem[2]);
sk->sk_rcvbuf = min(rcvmem, sock_net(sk)->ipv4.sysctl_tcp_rmem[2]);
}

/* 4. Try to fixup all. It is made immediately after connection enters
Expand Down Expand Up @@ -457,15 +457,16 @@ static void tcp_clamp_window(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
struct inet_connection_sock *icsk = inet_csk(sk);
struct net *net = sock_net(sk);

icsk->icsk_ack.quick = 0;

if (sk->sk_rcvbuf < sysctl_tcp_rmem[2] &&
if (sk->sk_rcvbuf < net->ipv4.sysctl_tcp_rmem[2] &&
!(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
!tcp_under_memory_pressure(sk) &&
sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)) {
sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
sysctl_tcp_rmem[2]);
net->ipv4.sysctl_tcp_rmem[2]);
}
if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
tp->rcv_ssthresh = min(tp->window_clamp, 2U * tp->advmss);
Expand Down Expand Up @@ -623,7 +624,8 @@ void tcp_rcv_space_adjust(struct sock *sk)
while (tcp_win_from_space(sk, rcvmem) < tp->advmss)
rcvmem += 128;

rcvbuf = min(rcvwin / tp->advmss * rcvmem, sysctl_tcp_rmem[2]);
rcvbuf = min(rcvwin / tp->advmss * rcvmem,
sock_net(sk)->ipv4.sysctl_tcp_rmem[2]);
if (rcvbuf > sk->sk_rcvbuf) {
sk->sk_rcvbuf = rcvbuf;

Expand Down
13 changes: 10 additions & 3 deletions net/ipv4/tcp_ipv4.c
View file
Expand Up @@ -2409,8 +2409,8 @@ struct proto tcp_prot = {
.memory_allocated = &tcp_memory_allocated,
.memory_pressure = &tcp_memory_pressure,
.sysctl_mem = sysctl_tcp_mem,
.sysctl_wmem = sysctl_tcp_wmem,
.sysctl_rmem = sysctl_tcp_rmem,
.sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
.sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
.max_header = MAX_TCP_HEADER,
.obj_size = sizeof(struct tcp_sock),
.slab_flags = SLAB_TYPESAFE_BY_RCU,
Expand Down Expand Up @@ -2509,7 +2509,14 @@ static int __net_init tcp_sk_init(struct net *net)
net->ipv4.sysctl_tcp_invalid_ratelimit = HZ/2;
net->ipv4.sysctl_tcp_pacing_ss_ratio = 200;
net->ipv4.sysctl_tcp_pacing_ca_ratio = 120;

if (net != &init_net) {
memcpy(net->ipv4.sysctl_tcp_rmem,
init_net.ipv4.sysctl_tcp_rmem,
sizeof(init_net.ipv4.sysctl_tcp_rmem));
memcpy(net->ipv4.sysctl_tcp_wmem,
init_net.ipv4.sysctl_tcp_wmem,
sizeof(init_net.ipv4.sysctl_tcp_wmem));
}
net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE;
spin_lock_init(&net->ipv4.tcp_fastopen_ctx_lock);
net->ipv4.sysctl_tcp_fastopen_blackhole_timeout = 60 * 60;
Expand Down
2 changes: 1 addition & 1 deletion net/ipv4/tcp_output.c
View file
Expand Up @@ -220,7 +220,7 @@ void tcp_select_initial_window(const struct sock *sk, int __space, __u32 mss,
(*rcv_wscale) = 0;
if (wscale_ok) {
/* Set window scaling on max possible window */
space = max_t(u32, space, sysctl_tcp_rmem[2]);
space = max_t(u32, space, sock_net(sk)->ipv4.sysctl_tcp_rmem[2]);
space = max_t(u32, space, sysctl_rmem_max);
space = min_t(u32, space, *window_clamp);
while (space > U16_MAX && (*rcv_wscale) < TCP_MAX_WSCALE) {
Expand Down
4 changes: 2 additions & 2 deletions net/ipv6/tcp_ipv6.c
View file
Expand Up @@ -1940,8 +1940,8 @@ struct proto tcpv6_prot = {
.memory_pressure = &tcp_memory_pressure,
.orphan_count = &tcp_orphan_count,
.sysctl_mem = sysctl_tcp_mem,
.sysctl_wmem = sysctl_tcp_wmem,
.sysctl_rmem = sysctl_tcp_rmem,
.sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
.sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
.max_header = MAX_TCP_HEADER,
.obj_size = sizeof(struct tcp6_sock),
.slab_flags = SLAB_TYPESAFE_BY_RCU,
Expand Down

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