Messages in this thread | | | Date | Tue, 9 Jan 2001 18:18:05 -0800 (PST) | From | Dave Zarzycki <> | Subject | Re: [PLEASE-TESTME] Zerocopy networking patch, 2.4.0-1 |
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On Tue, 9 Jan 2001, David S. Miller wrote:
> Ignore Ingo's comments about the MSG_NOCOPY flag, I've not included > those parts in the zerocopy patches as they are very controversial > and require some VM layer support.
Okay, I talked to some kernel engineers where I work and they were (I think) very justifiably skeptical of zero-copy work with respect to read/write style APIs.
> Basically, it pins the userspace pages, so if you write to them before > the data is fully sent and the networking buffer freed, they get > copied with a COW fault.
Yum... Assuming a gigabit ethernet link is saturated with the sendmsg(MSG_NOCOPY) API, what is CPU utilization like for a given clock speed and processor make? It is any different than the sendfile() case?
davez
-- Dave Zarzycki http://thor.sbay.org/~dave/
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