lkml.org 
[lkml]   [2006]   [Mar]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: TSO and IPoIB performance degradation
Quoting r. David S. Miller <davem@davemloft.net>:
> The path an SKB can take is opaque and unknown until the very last
> moment it is actually given to the device transmit function.

Why, I was proposing looking at dst cache. If that's NULL, well,
we won't stretch ACKs. Worst case we apply the wrong optimization.
Right?

> People need to get the "special case this topology" ideas out of their
> heads. :-)

Okay, I get that.

What I'd like to clarify, however: rfc2581 explicitly states that in some cases
it might be OK to generate ACKs less frequently than every second full-sized
segment. Given Matt's measurements, TCP on top of IP over InfiniBand on Linux
seems to hit one of these cases. Do you agree to that?

--
Michael S. Tsirkin
Staff Engineer, Mellanox Technologies
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-03-20 11:24    [W:2.755 / U:0.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site