sched: CHOKe flow scheduler
CHOKe ("CHOose and Kill" or "CHOose and Keep") is an alternative
packet scheduler based on the Random Exponential Drop (RED) algorithm.
The core idea is:
For every packet arrival:
Calculate Qave
if (Qave < minth)
Queue the new packet
else
Select randomly a packet from the queue
if (both packets from same flow)
then Drop both the packets
else if (Qave > maxth)
Drop packet
else
Admit packet with proability p (same as RED)
See also:
Rong Pan, Balaji Prabhakar, Konstantinos Psounis, "CHOKe: a stateless active
queue management scheme for approximating fair bandwidth allocation",
Proceeding of INFOCOM'2000, March 2000.
Help from:
Eric Dumazet <eric.dumazet@gmail.com>
Patrick McHardy <kaber@trash.net>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
index 776cd93..d4bb6f5 100644
--- a/include/linux/pkt_sched.h
+++ b/include/linux/pkt_sched.h
@@ -247,6 +247,35 @@
__u16 pad1;
};
+/* CHOKe section */
+
+enum {
+ TCA_CHOKE_UNSPEC,
+ TCA_CHOKE_PARMS,
+ TCA_CHOKE_STAB,
+ __TCA_CHOKE_MAX,
+};
+
+#define TCA_CHOKE_MAX (__TCA_CHOKE_MAX - 1)
+
+struct tc_choke_qopt {
+ __u32 limit; /* Hard queue length (packets) */
+ __u32 qth_min; /* Min average threshold (packets) */
+ __u32 qth_max; /* Max average threshold (packets) */
+ unsigned char Wlog; /* log(W) */
+ unsigned char Plog; /* log(P_max/(qth_max-qth_min)) */
+ unsigned char Scell_log; /* cell size for idle damping */
+ unsigned char flags; /* see RED flags */
+};
+
+struct tc_choke_xstats {
+ __u32 early; /* Early drops */
+ __u32 pdrop; /* Drops due to queue limits */
+ __u32 other; /* Drops due to drop() calls */
+ __u32 marked; /* Marked packets */
+ __u32 matched; /* Drops due to flow match */
+};
+
/* HTB section */
#define TC_HTB_NUMPRIO 8
#define TC_HTB_MAXDEPTH 8