[PATCH 0/2] mm: Use pte marker for swapin errors

From: Peter Xu
Date: Sun Oct 30 2022 - 17:43:03 EST


rfc->v1:
- Rename SWAP_ERROR -> SWAPIN_ERROR [David, Miaohe]
- Added r-bs for Ying and Miaohe

Hi,

This series uses the pte marker to replace the swapin error swap entry,
then we save one more swap entry slot for swap devices. A new pte marker
bit is defined.

One thing worth mentioning: we need the pte marker to be always built to
make sure it works like before, so I made an attempt in patch 1 to drop
CONFIG_PTE_MARKER and always compile pte marker in. Since pte markers are
enabled in many distributions by default already, meanwhile the codeset is
really small I assume it's fine. But still I'm tagging with RFC for this
initial version.

Smoke tested on anonymous mem on a fake swap failure. Please have a look,
thanks.

Peter Xu (2):
mm: Always compile in pte markers
mm: Use pte markers for swap errors

include/linux/swap.h | 16 ++++----------
include/linux/swapops.h | 49 +++++++++--------------------------------
mm/Kconfig | 7 ------
mm/memory.c | 13 ++++++-----
mm/shmem.c | 2 +-
mm/swapfile.c | 2 +-
6 files changed, 23 insertions(+), 66 deletions(-)

--
2.37.3