[SCTP]: Rewrite of sctp buffer management code

This patch introduces autotuning to the sctp buffer management code
similar to the TCP.  The buffer space can be grown if the advertised
receive window still has room.  This might happen if small message
sizes are used, which is common in telecom environmens.
New tunables are introduced that provide limits to buffer growth
and memory pressure is entered if to much buffer spaces is used.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 0 deletions

diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index e2c679baf912..ba75ef4669e3 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -52,6 +52,15 @@ static int int_max = INT_MAX;
 static long sack_timer_min = 1;
 static long sack_timer_max = 500;
 
+int sysctl_sctp_mem[3];
+int sysctl_sctp_rmem[3];
+int sysctl_sctp_wmem[3];
+
+/*
+ * per assoc memory limitationf for sends
+ */
+int sysctl_sctp_wmem[3];
+
 static ctl_table sctp_table[] = {
         {
                 .ctl_name       = NET_SCTP_RTO_INITIAL,
@@ -226,6 +235,30 @@ static ctl_table sctp_table[] = {
                 .extra1         = &sack_timer_min,
                 .extra2         = &sack_timer_max,
         },
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "sctp_mem",
+                .data           = &sysctl_sctp_mem,
+                .maxlen         = sizeof(sysctl_sctp_mem),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+        },
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "sctp_rmem",
+                .data           = &sysctl_sctp_rmem,
+                .maxlen         = sizeof(sysctl_sctp_rmem),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+        },
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "sctp_wmem",
+                .data           = &sysctl_sctp_wmem,
+                .maxlen         = sizeof(sysctl_sctp_wmem),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+        },
         { .ctl_name = 0 }
 };