net_sched: sfq: extend limits
SFQ as implemented in Linux is very limited, with at most 127 flows
and limit of 127 packets. [ So if 127 flows are active, we have one
packet per flow ]
This patch brings to SFQ following features to cope with modern needs.
- Ability to specify a smaller per flow limit of inflight packets.
(default value being at 127 packets)
- Ability to have up to 65408 active flows (instead of 127)
- Ability to have head drops instead of tail drops
(to drop old packets from a flow)
Example of use : No more than 20 packets per flow, max 8000 flows, max
20000 packets in SFQ qdisc, hash table of 65536 slots.
tc qdisc add ... sfq \
flows 8000 \
depth 20 \
headdrop \
limit 20000 \
divisor 65536
Ram usage :
2 bytes per hash table entry (instead of previous 1 byte/entry)
32 bytes per flow on 64bit arches, instead of 384 for QFQ, so much
better cache hit ratio.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Dave Taht <dave.taht@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 8daced3..8f1b928 100644
--- a/include/linux/pkt_sched.h
+++ b/include/linux/pkt_sched.h
@@ -162,19 +162,17 @@
unsigned flows; /* Maximal number of flows */
};
+struct tc_sfq_qopt_v1 {
+ struct tc_sfq_qopt v0;
+ unsigned int depth; /* max number of packets per flow */
+ unsigned int headdrop;
+};
+
+
struct tc_sfq_xstats {
__s32 allot;
};
-/*
- * NOTE: limit, divisor and flows are hardwired to code at the moment.
- *
- * limit=flows=128, divisor=1024;
- *
- * The only reason for this is efficiency, it is possible
- * to change these parameters in compile time.
- */
-
/* RED section */
enum {