mbox series

[v2,0/3] cleanup of SLAB_ flags

Message ID 20240223-slab-cleanup-flags-v2-0-02f1753e8303@suse.cz
Headers
Series cleanup of SLAB_ flags |

Message

Vlastimil Babka Feb. 23, 2024, 6:27 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 <vbabka@suse.cz>
---
Changes in v2:
- Collect R-b, T-b (thanks!)
- Unify all disabled flags's value to a sparse-happy zero with a new macro (lkp/sparse).
- Rename __SF_BIT to __SLAB_FLAG_BIT (Roman Gushchin)
- Rewrod kasan_cache_create() comment (Andrey Konovalov)
- Link to v1: https://lore.kernel.org/r/20240220-slab-cleanup-flags-v1-0-e657e373944a@suse.cz

---
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  | 97 ++++++++++++++++++++++++++++++++++++---------------
 mm/kasan/generic.c    | 22 ++++--------
 mm/slab.h             |  1 -
 mm/slab_common.c      |  2 +-
 mm/slub.c             |  6 ++--
 6 files changed, 79 insertions(+), 55 deletions(-)
---
base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d
change-id: 20240219-slab-cleanup-flags-c864415ecc8e

Best regards,

Comments

Vlastimil Babka Feb. 26, 2024, 9:11 a.m. UTC | #1 
On 2/23/24 19:27, Vlastimil Babka wrote:
> 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 <vbabka@suse.cz>

Pushed to slab/for-next

> ---
> Changes in v2:
> - Collect R-b, T-b (thanks!)
> - Unify all disabled flags's value to a sparse-happy zero with a new macro (lkp/sparse).
> - Rename __SF_BIT to __SLAB_FLAG_BIT (Roman Gushchin)
> - Rewrod kasan_cache_create() comment (Andrey Konovalov)
> - Link to v1: https://lore.kernel.org/r/20240220-slab-cleanup-flags-v1-0-e657e373944a@suse.cz
> 
> ---
> 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  | 97 ++++++++++++++++++++++++++++++++++++---------------
>  mm/kasan/generic.c    | 22 ++++--------
>  mm/slab.h             |  1 -
>  mm/slab_common.c      |  2 +-
>  mm/slub.c             |  6 ++--
>  6 files changed, 79 insertions(+), 55 deletions(-)
> ---
> base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d
> change-id: 20240219-slab-cleanup-flags-c864415ecc8e
> 
> Best regards,