tcp: allow for bigger reordering level
While testing upcoming Yaogong patch (converting out of order queue
into an RB tree), I hit the max reordering level of linux TCP stack.
Reordering level was limited to 127 for no good reason, and some
network setups [1] can easily reach this limit and get limited
throughput.
Allow a new max limit of 300, and add a sysctl to allow admins to even
allow bigger (or lower) values if needed.
[1] Aggregation of links, per packet load balancing, fabrics not doing
deep packet inspections, alternative TCP congestion modules...
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yaogong Wang <wygivan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index c2dee7d..f566b85 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -204,10 +204,10 @@
u16 urg_data; /* Saved octet of OOB data and control flags */
u8 ecn_flags; /* ECN status bits. */
- u8 reordering; /* Packet reordering metric. */
+ u8 keepalive_probes; /* num of allowed keep alive probes */
+ u32 reordering; /* Packet reordering metric. */
u32 snd_up; /* Urgent pointer */
- u8 keepalive_probes; /* num of allowed keep alive probes */
/*
* Options received (usually on last packet, some only on SYN packets).
*/