WLAN subsystem: Sysctl support for key TCP/IP parameters
It has been observed that default values for some of key tcp/ip
parameters are affecting the tput/performance of the system. Hence
extending configuration capabilities to TCP/Ip stack through
sysctl interface.
Change-Id: I0c99d5b50cbe0d6496e40d391eacc12b0c62dbed
CRs-Fixed: 507581
Signed-off-by: Mahesh A Saptasagar <msapta@codeaurora.org>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 50660b3..4ab18e0 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -130,6 +130,8 @@
* valid RTT sample has been acquired,
* most likely due to retrans in 3WHS.
*/
+/* Number of full MSS to receive before Acking RFC2581 */
+#define TCP_DELACK_SEG 1
#define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes
* for local resources.
@@ -254,6 +256,10 @@
extern int sysctl_tcp_thin_dupack;
extern atomic_long_t tcp_memory_allocated;
+
+/* sysctl variables for controlling various tcp parameters */
+extern int sysctl_tcp_delack_seg;
+extern int sysctl_tcp_use_userconfig;
extern struct percpu_counter tcp_sockets_allocated;
extern int tcp_memory_pressure;
@@ -345,6 +351,11 @@
extern ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags);
+/* sysctl master controller */
+extern int tcp_use_userconfig_sysctl_handler(struct ctl_table *, int,
+ void __user *, size_t *, loff_t *);
+extern int tcp_proc_delayed_ack_control(struct ctl_table *, int,
+ void __user *, size_t *, loff_t *);
static inline void tcp_dec_quickack_mode(struct sock *sk,
const unsigned int pkts)
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 7a7724d..3171f7f 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -36,6 +36,10 @@
static int ip_ttl_max = 255;
static int ip_ping_group_range_min[] = { 0, 0 };
static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
+static int tcp_delack_seg_min = TCP_DELACK_MIN;
+static int tcp_delack_seg_max = 60;
+static int tcp_use_userconfig_min;
+static int tcp_use_userconfig_max = 1;
/* Update system visible IP port range */
static void set_local_port_range(int range[2])
@@ -699,6 +703,25 @@
.proc_handler = proc_dointvec_minmax,
.extra1 = &zero
},
+ {
+ .procname = "tcp_delack_seg",
+ .data = &sysctl_tcp_delack_seg,
+ .maxlen = sizeof(sysctl_tcp_delack_seg),
+ .mode = 0644,
+ .proc_handler = tcp_proc_delayed_ack_control,
+ .extra1 = &tcp_delack_seg_min,
+ .extra2 = &tcp_delack_seg_max,
+ },
+ {
+ .procname = "tcp_use_userconfig",
+ .data = &sysctl_tcp_use_userconfig,
+ .maxlen = sizeof(sysctl_tcp_use_userconfig),
+ .mode = 0644,
+ .proc_handler = tcp_use_userconfig_sysctl_handler,
+ .extra1 = &tcp_use_userconfig_min,
+ .extra2 = &tcp_use_userconfig_max,
+ },
+
{ }
};
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 74a286c..b2458f2 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -296,6 +296,11 @@
atomic_long_t tcp_memory_allocated; /* Current allocated memory. */
EXPORT_SYMBOL(tcp_memory_allocated);
+int sysctl_tcp_delack_seg __read_mostly = TCP_DELACK_SEG;
+EXPORT_SYMBOL(sysctl_tcp_delack_seg);
+
+int sysctl_tcp_use_userconfig __read_mostly;
+EXPORT_SYMBOL(sysctl_tcp_use_userconfig);
/*
* Current number of TCP sockets.
@@ -1213,8 +1218,11 @@
/* Delayed ACKs frequently hit locked sockets during bulk
* receive. */
if (icsk->icsk_ack.blocked ||
- /* Once-per-two-segments ACK was not sent by tcp_input.c */
- tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
+ /* Once-per-sysctl_tcp_delack_segments
+ * ACK was not sent by tcp_input.c
+ */
+ tp->rcv_nxt - tp->rcv_wup > (icsk->icsk_ack.rcv_mss) *
+ sysctl_tcp_delack_seg ||
/*
* If this read emptied read buffer, we send ACK, if
* connection is not bidirectional, user drained
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 257b617..7c3612b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5047,7 +5047,8 @@
struct tcp_sock *tp = tcp_sk(sk);
/* More than one full frame received... */
- if (((tp->rcv_nxt - tp->rcv_wup) > inet_csk(sk)->icsk_ack.rcv_mss &&
+ if (((tp->rcv_nxt - tp->rcv_wup) > (inet_csk(sk)->icsk_ack.rcv_mss) *
+ sysctl_tcp_delack_seg &&
/* ... and right edge of window advances far enough.
* (tcp_recvmsg() will send ACK otherwise). Or...
*/
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 34d4a02..750926d 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -36,6 +36,36 @@
static void tcp_delack_timer(unsigned long);
static void tcp_keepalive_timer (unsigned long data);
+/*Function to reset tcp_ack related sysctl on resetting master control */
+void set_tcp_default(void)
+{
+ sysctl_tcp_delack_seg = TCP_DELACK_SEG;
+}
+
+/*sysctl handler for tcp_ack realted master control */
+int tcp_proc_delayed_ack_control(ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ int ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ /* The ret value will be 0 if the input validation is successful
+ * and the values are written to sysctl table. If not, the stack
+ * will continue to work with currently configured values
+ */
+ return ret;
+}
+
+/*sysctl handler for tcp_ack realted master control */
+int tcp_use_userconfig_sysctl_handler(ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ int ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ if (write && ret == 0) {
+ if (!sysctl_tcp_use_userconfig)
+ set_tcp_default();
+ }
+ return ret;
+}
+
void tcp_init_xmit_timers(struct sock *sk)
{
inet_csk_init_xmit_timers(sk, &tcp_write_timer, &tcp_delack_timer,