Re: [PATCH v3 3/3] infiniband/mm: convert put_page() to put_user_page*()

[Jason Gunthorpe]

On Fri, Oct 05, 2018 at 07:49:49PM -0700, john.hubbard@xxxxxxxxx wrote:
> From: John Hubbard <jhubbard@xxxxxxxxxx>
> 
> For code that retains pages via get_user_pages*(),
> release those pages via the new put_user_page(), or
> put_user_pages*(), instead of put_page()
> 
> This prepares for eventually fixing the problem described
> in [1], and is following a plan listed in [2], [3], [4].
> 
> [1] https://lwn.net/Articles/753027/ : "The Trouble with get_user_pages()"
> 
> [2] https://lkml.kernel.org/r/20180709080554.21931-1-jhubbard@xxxxxxxxxx
>     Proposed steps for fixing get_user_pages() + DMA problems.
> 
> [3]https://lkml.kernel.org/r/20180710082100.mkdwngdv5kkrcz6n@xxxxxxxxxxxxxx
>     Bounce buffers (otherwise [2] is not really viable).
> 
> [4] https://lkml.kernel.org/r/20181003162115.GG24030@xxxxxxxxxxxxxx
>     Follow-up discussions.
> 
> CC: Doug Ledford <dledford@xxxxxxxxxx>
> CC: Jason Gunthorpe <jgg@xxxxxxxx>
> CC: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
> CC: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
> CC: Christian Benvenuti <benve@xxxxxxxxx>
> 
> CC: linux-rdma@xxxxxxxxxxxxxxx
> CC: linux-kernel@xxxxxxxxxxxxxxx
> CC: linux-mm@xxxxxxxxx
> Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
> ---
>  drivers/infiniband/core/umem.c              |  7 ++++---
>  drivers/infiniband/core/umem_odp.c          |  2 +-
>  drivers/infiniband/hw/hfi1/user_pages.c     | 11 ++++-------
>  drivers/infiniband/hw/mthca/mthca_memfree.c |  6 +++---
>  drivers/infiniband/hw/qib/qib_user_pages.c  | 11 ++++-------
>  drivers/infiniband/hw/qib/qib_user_sdma.c   |  8 ++++----
>  drivers/infiniband/hw/usnic/usnic_uiom.c    |  7 ++++---
>  7 files changed, 24 insertions(+), 28 deletions(-)

I have no issues with this, do you want this series to go through the
rdma tree? Otherwise:

Acked-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>

Thanks,
Jason