[RFC,v2,0/3] mm/gup: introduce vaddr_pin_pages_remote(), FOLL_PIN

Message

John Hubbard Aug. 17, 2019, 2:24 a.m. UTC

From: John Hubbard <[e-mail]>

Hi Ira,

As requested, this is for your tree:
https://github.com/weiny2/linux-kernel.git (mmotm-rdmafsdax-b0-v4), to be
applied at your last authored commit, which is: commit f625f92ecfb4
("mm/gup: Remove FOLL_LONGTERM DAX exclusion"). In other words, please
delete my previous patches from the tree, and apply these replacement
patches.

This now has a user for the new vaddr_pin_user_pages_remote() call. And
it also moves the gup flag setting out to the caller.

I'm pretty pleased to be able to include a bit of documentation (see the
FOLL_PIN patch) that covers those four cases. This should really help
clarify things. Thanks to Jan Kara and Vlastimil Babka for providing
the meaingful core of that documentation.

The naming can of course be tweaked to match whatever the final is. For
now, I've used vaddr_pin_user_pages_remote(). That addresses Jason's
request for a "user" in the name, and it also makes it very clear that
it's a replacement for get_user_pages_remote().

v1 of this RFC is here:
https://lore.kernel.org/r/[e-mail]

John Hubbard (3):
  For Ira: tiny formatting tweak to kerneldoc
  mm/gup: introduce FOLL_PIN flag for get_user_pages()
  mm/gup: introduce vaddr_pin_pages_remote(), and invoke it

 include/linux/mm.h     | 61 +++++++++++++++++++++++++++++++++++++-----
 mm/gup.c               | 37 +++++++++++++++++++++++--
 mm/process_vm_access.c | 23 +++++++++-------
 3 files changed, 104 insertions(+), 17 deletions(-)