[PATCH v2 0/5] fork: Page operation cleanups in the fork code

[Linus Walleij <linus.walleij@linaro.org>]

This patch set consists of outtakes from a 1 year+ old
patch set from Pasha, which all stand on their own.
See:
https://lore.kernel.org/all/20240311164638.2015063-1-pasha.tatashin@soleen.com/

What the code mainly does is make the fork.c file more
oriented around pages and remove reliance on THREAD_SIZE.

These are good cleanups for readability and in one case
(last patch using clear_page()) a performance improvement,
so I split these off, rebased on v6.15-rc1, addressed review
comments and send them separately.

All mentions of dynamic stack are removed from the patch
set as we have no idea whether that will go anywhere.

This is mostly MM related so when the patches are ready
I expect they would land in Andrew's patch stack.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
Changes in v2:
- Fix subject on patch 2/5
- Fix bisect problem in BUG() guard in patch 2/5
- Move back to using a local nr_pages variable in
  patch 3/5 for performance concerns.
- Use preferred patch augment format.
- Link to v1: https://lore.kernel.org/r/20250506-fork-fixes-v1-0-bd35b63f0f1b@linaro.org

---
Pasha Tatashin (5):
      fork: Clean-up ifdef logic around stack allocation
      fork: Clean-up naming of vm_stack/vm_struct variables in vmap stacks code
      fork: Remove assumption that vm_area->nr_pages equals to THREAD_SIZE
      fork: check charging success before zeroing stack
      fork: zero vmap stack using clear_page() instead of memset()

 kernel/fork.c | 103 +++++++++++++++++++++++++++++-----------------------------
 1 file changed, 52 insertions(+), 51 deletions(-)
---
base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
change-id: 20250504-fork-fixes-9378b6c57873

Best regards,
-- 
Linus Walleij <linus.walleij@linaro.org>