sctp: Update SWS avaoidance receiver side algorithm
We currently send window update SACKs every time we free up 1 PMTU
worth of data. That a lot more SACKs then necessary. Instead, we'll
now send back the actuall window every time we send a sack, and do
window-update SACKs when a fraction of the receive buffer has been
opened. The fraction is controlled with a sysctl.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index ab7151d..ae03ded 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -52,6 +52,7 @@
static int sack_timer_min = 1;
static int sack_timer_max = 500;
static int addr_scope_max = 3; /* check sctp_scope_policy_t in include/net/sctp/constants.h for max entries */
+static int rwnd_scale_max = 16;
extern int sysctl_sctp_mem[3];
extern int sysctl_sctp_rmem[3];
@@ -284,6 +285,18 @@
.extra1 = &zero,
.extra2 = &addr_scope_max,
},
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "rwnd_update_shift",
+ .data = &sctp_rwnd_upd_shift,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_minmax,
+ .strategy = &sysctl_intvec,
+ .extra1 = &one,
+ .extra2 = &rwnd_scale_max,
+ },
+
{ .ctl_name = 0 }
};