Re: 2.6 upgrade overall failure report

["David S. Miller" <davem@davemloft.net>]

On Fri, 29 Apr 2005 02:17:56 -0700
Andrew Morton <akpm@osdl.org> wrote:

> >  . There is still a memory leak trouble (probably in tigon3 driver since others
> >    reported so on kernel mailing list, and tigon3 is not a geek hardware since
> >    most nowdays lowend servers use either tigon3 or pro1000)
> 
> Please send a report to David Miller and Jeff Garzik and cc netdev@oss.sgi.com

This is the first I've ever heard of any such leak, more likely
the leak is in the networking code somewhere.

> >  . Since 2.6.10, the TCP task does not work anymore with OSX (2 Mbps instead
> >    of 60 Mbps on a 100 Mbps wire)
> 
> Please send a full report to David Miller and cc netdev@oss.sgi.com.
> 
> Also please describe a simple way of reproducing this - I'll see if it
> happens here.

It only happens with OS-X and it has to do with how they handle the fast
path of TCP input.  It's a known problem but no satisfatory solution
exists yet.  When the fast path in OS-X TCP input is hit, they always
delay ACKs by a full 500ms, there isn't much Linux can do about broken
behavior like that.

We are thinking of possible workarounds, but this bug is very low priority
since it is really a MAC OS-X issue.

Anyways, I'm in Chicago until Monday so won't be able to look into anything
in detail until then.