[openib-general] ib_unmap_fmr

[Sean Hefty]

On Wed, 01 Sep 2004 18:41:44 -0700
Roland Dreier <roland at topspin.com> wrote:

> One of the main reasons that FMRs (in the Mellanox Tavor sense) are a
> win is that the cost of flushing the HCA's memory mapping cache can be
> amortized across multiple FMRs with a single unmap call.  So having
> unmap_fmr operate on multiple FMRs at once is central to its
> usefulness.

Got it.  I guess I need to look closer at the implementation.  Does the flushing occur when unmapped is called, or is the flushing done at some later point?  I was under the impression that it was the latter, but I could be wrong.

> With that said I prefer using a linked list (and that's what I have on
> my branch), and I agree with the assumption that all the FMRs come
> from the same device.

I did notice that your branch used a linked list, which seemed to make more sense to me than using an array.