Subject: 2.6.17 regression: Very slow net transfer from some hosts

From: Daniel Drake <[email-masked]>
Date: Tue, 11 Apr 2006 20:30:46 +0100

Hi,

Since sometime after 2.6.16, some websites have been very slow to load. 
  Examples include:

http://zd1211.ath.cx
http://developer.osdl.org/shemminger/blog/
http://www.reactivated.net/weblog

On a good kernel, "wget http://zd1211.ath.cx" says:
20:23:38 (90.44 KB/s) - `index.html' saved [20895/20895]

On a bad kernel:
20:14:18 (327.01 B/s) - `index.html' saved [20895/20895]

I reproduced this on two different internet connections (same ISP 
though). However I cannot reproduce it on my other system.

git-bisect tracked it down to:

7b4f4b5ebceab67ce440a61081a69f0265e17c2a is first bad commit
diff-tree 7b4f4b5ebceab67ce440a61081a69f0265e17c2a (from 
2babf9daae4a3561f3264638a22ac7d0b14a6f52)
Author: John Heffner <[email-masked]>
Date:   Sat Mar 25 01:34:07 2006 -0800

     [TCP]: Set default max buffers from memory pool size

Indeed, reverting this patch from 2.6.17-rc1-git4 allows those sites to 
load again.

Any ideas?

Thanks,
Daniel