Messages in this thread |  | | From | Bharath Madhavan <> | Subject | RE: Accelerated TCP/IP support from kernel | Date | Thu, 24 May 2001 18:50:53 -0400 |
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Thanks a lot. That was useful info especially your last point where you are saying that most of the area we can save is in data processing and not in protocol processing. So, if we use the ZERO_COPY feature, we should gain quite a bit. I guess 3c905c NIC supports HW checksumming. Is this true? In this case, do we have any benchmarking for this card with and without ZERO_COPY (and HW checksumming). I am eager to know by how many times did the system throughput increase? Thanks a lot Bharath
-----Original Message----- From: David S. Miller [mailto:davem@redhat.com] Sent: Thursday, May 24, 2001 6:29 PM To: Bharath Madhavan Cc: linux-kernel@vger.kernel.org Subject: Re: Accelerated TCP/IP support from kernel
Bharath Madhavan writes: > I am looking into a scenario where we have a NIC which performs > all the TCP/IP processing and basically the core CPU offloads all data from > the socket level interface onwards to this NIC.
Why would you ever want to do this?
Point 1: Support for new TCP techniques and bug fixes are hard enough to propagate to user's systems as it is with the implementation being done in software.
Point 2: If I find a bug in the cards TCP implementation, will I be able to get at the source for the firmware and fix it? Likely the answer to this is no.
Every couple years a few vendors make cards like this, yet ignore these core issues. It is currently impractical to use these kinds of cards today except in a few very special case situations.
Furthermore, the actual protocol processing overhead is quite small and almost neglible especially on today's gigahertz beasts. The data copy is where the time is spent, and checksum offload takes care of that.
Later, David S. Miller davem@redhat.com - 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/ - 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/
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