[v3,0/3] A few gup refactorings and documentation updates

Message

John Hubbard Aug. 13, 2021, 4:41 a.m. UTC

Here is what's new for v3:

* Removed __maybe_unused from try_grab_compound_head
* Removed some unnecessary comparisons against NULL.
* Added Christoph's Reviewed-by tags to patches 2 and 3

Changes in v2:

* Changed refs to @refs, and added some more documentation as well.
* Completely removed try_get_page(). (I'm adding more people and lists
  to Cc, because of those call site changes.) * Reversed the logic in
try_grab_page() to make it a touch more
  readable.
* Rebased to linux-next (next-20210810).

Original v2 is here:
https://lore.kernel.org/r/[e-mail]

Here is the v1 cover letter, edited slightly to keep up with the latest
story.

While reviewing some of the other things going on around gup.c, I
noticed that the documentation was wrong for a few of the routines that
I wrote. And then I noticed that there was some significant code
duplication too. So this fixes those issues.

This is not entirely risk-free, but after looking closely at this, I
think it's actually a useful improvement, getting rid of the code
duplication here.

However, it is possible I've overlooked something. I did some local LTP
and other testing on an x86 test machine but failed to find any problems
yet.

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



John Hubbard (3):
  mm/gup: documentation corrections for gup/pup
  mm/gup: small refactoring: simplify try_grab_page()
  mm/gup: Remove try_get_page(), call try_get_compound_head() directly

 arch/s390/mm/fault.c |  2 +-
 fs/pipe.c            |  2 +-
 include/linux/mm.h   | 14 ++------
 mm/gup.c             | 83 ++++++++++++++++++++++----------------------
 4 files changed, 47 insertions(+), 54 deletions(-)