Re: [PATCH] fix limited slow start bug

From: John Heffner <redacted>
Date: Thu, 22 Feb 2007 16:52:03 -0500

I think it's not unreasonable to change clamp to 32 bits now, since with 
1500 byte packets, this corresponds to a max cwnd of ~94MB.  This is 
pretty big, but we are currently right at this limit with 10 GigE.

Agreed, and done in tcp-2.6.git as below.

What should we do about that 65535 assignment in hybla?

commit cedfa95566512730202bb4abed5d9118e74bab30
Author: David S. Miller [off-list ref]
Date:   Thu Feb 22 22:52:59 2007 -0800

    [TCP]: Make snd_cwnd_clamp a u32.
    
    Signed-off-by: David S. Miller [off-list ref]

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 415193e..18a468d 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h

@@ -302,7 +302,7 @@ struct tcp_sock {
  	u32	snd_ssthresh;	/* Slow start size threshold		*/
  	u32	snd_cwnd;	/* Sending congestion window		*/
  	u16	snd_cwnd_cnt;	/* Linear increase counter		*/
-	u16	snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
+	u32	snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
 	u32	snd_cwnd_used;
 	u32	snd_cwnd_stamp;