Re: [PATCH rdma-next v5 0/4] Dynamicaly allocate SG table from the pages

[Jason Gunthorpe]

On Sun, Oct 04, 2020 at 06:43:36PM +0300, Leon Romanovsky wrote:
> This series extends __sg_alloc_table_from_pages to allow chaining of
> new pages to already initialized SG table.
> 
> This allows for the drivers to utilize the optimization of merging contiguous
> pages without a need to pre allocate all the pages and hold them in
> a very large temporary buffer prior to the call to SG table initialization.
> 
> The second patch changes the Infiniband driver to use the new API. It
> removes duplicate functionality from the code and benefits the
> optimization of allocating dynamic SG table from pages.
> 
> In huge pages system of 2MB page size, without this change, the SG table
> would contain x512 SG entries.
> E.g. for 100GB memory registration:
> 
>              Number of entries      Size
>     Before        26214400          600.0MB
>     After            51200            1.2MB
> 
> Thanks
> 
> Maor Gottlieb (2):
>   lib/scatterlist: Add support in dynamic allocation of SG table from
>     pages
>   RDMA/umem: Move to allocate SG table from pages
> 
> Tvrtko Ursulin (2):
>   tools/testing/scatterlist: Rejuvenate bit-rotten test
>   tools/testing/scatterlist: Show errors in human readable form

This looks OK, I'm going to send it into linux-next on the hmm tree
for awhile to see if anything gets broken. If there is more
remarks/tags/etc please continue

Thanks,
Jason