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

From: Stephen Hemminger
Date: Tue Apr 11 2006 - 15:21:56 EST


On Tue, 11 Apr 2006 20:30:46 +0100
Daniel Drake <dsd@xxxxxxxxxx> wrote:

> 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 <jheffner@xxxxxxx>
> 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?

Get a tcpdump. There are tools to sanitize the file if you worry about
ip addresses, etc.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/