David Miller wrote:
From: "Waskiewicz Jr, Peter P" <[EMAIL PROTECTED]>
Date: Thu, 11 Oct 2007 16:27:14 -0700
I'm having an issue with TSO right vs. hardware that can't take the
maximum segment size sent from the stack. I've been told that the
maximum packet size that can be sent to the hardware today is 64k, but
my hardware can only take 32k in certain modes per queue due to hardware
limitations.
Bletch.
I have two questions regarding this: 1) where is this
value set in the TCP code, and 2) Is this something that can be
configured on the fly? If the answer to 2 is no, I will try and put
something together to allow this to happen.
The TCP code just builds the maximum possible for the underlying
protocol, be it ipv4 or ipv6. It takes the underlying protocol
maximum packet length, subtracts the amount of header space it
knows will be used, and uses that.
You'll need to use GSO sw segmentation to split the TSO packets
which are too big for your HW to handle.
For just messing about, might it be possible to tweak the socket buffer sizes
and tcp_tso_win_divisor to kludge things for a short while? Couldn't ship that
way certainly, but assuming Peter's going to get his broken hardware fixed it
might let him limp along until then.
rick jones
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
