[0/3] cleanup of SLAB_ flags

Message

Vlastimil Babka Feb. 20, 2024, 4:58 p.m. UTC

This started by the report that SLAB_MEM_SPREAD flag is dead (Patch 1).
Then in the alloc profiling series we realized it's too easy to reuse an
existing SLAB_ flag's value when defining a new one, by mistake.
Thus let the compiler do that for us via a new helper enum (Patch 2).
When checking if more flags are dead or could be removed, didn't spot
any, but found out the SLAB_KASAN handling of preventing cache merging
can be simplified since we now have an explicit SLAB_NO_MERGE (Patch 3).

The SLAB_MEM_SPREAD flag is now marked as unused and for removal, and
has a value of 0 so it's a no-op. Patches to remove its usage can/will
be submitted to respective subsystems independently of this series - the
flag is already dead as of v6.8-rc1 with SLAB removed. The removal of
dead cpuset_do_slab_mem_spread() code can also be submitted
independently.

Signed-off-by: Vlastimil Babka <[e-mail]>
---
Vlastimil Babka (3):
      mm, slab: deprecate SLAB_MEM_SPREAD flag
      mm, slab: use an enum to define SLAB_ cache creation flags
      mm, slab, kasan: replace kasan_never_merge() with SLAB_NO_MERGE

 include/linux/kasan.h |  6 ----
 include/linux/slab.h  | 86 +++++++++++++++++++++++++++++++++++++--------------
 mm/kasan/generic.c    | 16 +++-------
 mm/slab.h             |  1 -
 mm/slab_common.c      |  2 +-
 mm/slub.c             |  6 ++--
 6 files changed, 71 insertions(+), 46 deletions(-)
---
base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d
change-id: 20240219-slab-cleanup-flags-c864415ecc8e

Best regards,