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Date: Thu, 22 Feb 2001 22:48:49 +0100
From: Pavel Machek <pavel@suse.cz>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>, Nye Liu <nyet@curtis.curtisfong.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Very high bandwith packet based interface and performance problems
In-Reply-To: <20010221140055.A8113@curtis.curtisfong.org> <E14VhQ7-0002s0-00@the-village.bc.nu>
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Hi!

> > This is NOT what I'm seeing at all.. the kernel load appears to be
> > pegged at 100% (or very close to it), the user space app is getting
> > enough cpu time to read out about 10-20Mbit, and FURTHERMORE the kernel
> > appears to be ACKING ALL the traffic, which I don't understand at all
> > (e.g. the transmitter is simply blasting 300MBit of tcp unrestricted)
> 
> TCP _requires_ the remote end ack every 2nd frame regardless of
> progress.

Should not TCP advertise window of 0 to stop sender?

Where does kernel put all those data in tcp case? I do not understand
that. Transmiter blasts at 300Mbit, userspace gets 20Mbit. There's
280Mbit datastream going _somewhere_. It should be eating memory at
35MB/second, unless you have 1Gig of ram, something interesting should
happen after minute or so...
								Pavel
-- 
I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org
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