[0/2] mm/gup + IB: allow FOLL_FORCE for gup_fast and use in IB

Message

John Hubbard Nov. 25, 2019, 12:37 a.m. UTC

Hi Leon, Jason, Christoph,

Maybe I'm overlooking something, but as I wrote in patch 1, it looks
like we can simply allow FOLL_FORCE to be passed to gup_fast().

This should fix Leon's reported RDMA failure [1]  when using patch 2 by
itself. (I've compile- and boot-tested these, and also did short LTP
and fio with direct IO tests, but I don't have an Infiniband runtime
setup that exercises the umem.c code.)

[1] https://lore.kernel.org/r/20191124100724.GH136476@unreal

John Hubbard (2):
  mm/gup: allow FOLL_FORCE for get_user_pages_fast()
  IB/umem: use get_user_pages_fast() to pin DMA pages

 drivers/infiniband/core/umem.c | 17 ++++++-----------
 mm/gup.c                       |  3 ++-
 2 files changed, 8 insertions(+), 12 deletions(-)

Comments

John Hubbard Nov. 25, 2019, 2:07 a.m. UTC | #1

On 11/24/19 4:37 PM, John Hubbard wrote:
> Hi Leon, Jason, Christoph,
> 
> Maybe I'm overlooking something, but as I wrote in patch 1, it looks
> like we can simply allow FOLL_FORCE to be passed to gup_fast().
> 
> This should fix Leon's reported RDMA failure [1]  when using patch 2 by
> itself. (I've compile- and boot-tested these, and also did short LTP
> and fio with direct IO tests, but I don't have an Infiniband runtime
> setup that exercises the umem.c code.)
> 
> [1] https://lore.kernel.org/r/20191124100724.GH136476@unreal
> 
> John Hubbard (2):
>   mm/gup: allow FOLL_FORCE for get_user_pages_fast()
>   IB/umem: use get_user_pages_fast() to pin DMA pages
> 
>  drivers/infiniband/core/umem.c | 17 ++++++-----------
>  mm/gup.c                       |  3 ++-
>  2 files changed, 8 insertions(+), 12 deletions(-)
> 

OK, based on Jason's response [1] that it's too late to put this into
5.5, let's withdraw this, and I'll resend when it's time to send out
patches for 5.6.

[1] https://lore.kernel.org/r/[e-mail]

thanks,