Re: [Qemu-devel] [PATCH v3 09/12] iov: add iov_get_ptr() to reference vector data

[Paolo Bonzini]

Il 22/11/2012 10:45, Michael S. Tsirkin ha scritto:
> All this looks suspiciously like premature optimization to me.
> Do we have data to show avoiding header copy is a win?

The code is a little simpler, because we know the footer is 1 byte only.

Paolo

> The caller would have to handle the case where the header is not
> contigious, which seems just too complex - in practice the code
> seems to simply fail in this case.
> 
> Why not just copy the header using iov_from_buf()/iov_to_buf()
> and be done with it?