Re: copy_from_user() overhead

Tim Hockin (
Fri, 28 Sep 2001 00:38:26 -0700 (PDT)

> We are interested in finding out the overhead in kernel->user buffer copy and
> vice-versa for disk reads and network writes resp. in copy_from_user() and
> copy_to_user() calls. Are there any quantitative data available for this? We
> plan to eliminate this overhead, if significant, in our integrated disk-read and
> network-write architecture. Any pointers/references related to this type of
> work?

Perhaps you are thinking of something like IO-Lite? Has anyone in the
linux world ever implemented IO-Lite? Sure would be interesting to have
essentially zero-copy file operations..
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