Re: [PATCH 05/11] slab: Use memdesc_flags_t

[Zi Yan <ziy@nvidia.com>]

On 5 Aug 2025, at 13:22, Matthew Wilcox (Oracle) wrote:

> The slab flags are memdesc flags and contain the same information in the
> upper bits as the other memdescs (like node ID).

Yeah, SLAB_MATCH(flags, flags) checks for that. Ideally, we might want to
use the same type for the shared part and different types for struct specific
fields. But that would fiddle with struct variable bit width.

Something like

typedef struct {
	unsigned long loc : SECTIONS_WIDTH + NODES_WIDTH + ZONES_WIDTH + ...;
    union {
		folio_flags_t folio_flags : FOLIO_FLAGS_WIDTH;
		slab_flags_t slab_flags : SLAB_FLAGS_WIDTH;
		...
    };
} memdesc_flags_t;

Hmm, seems very complicated. Never mind. ;)

>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>  mm/slab.h |  2 +-
>  mm/slub.c | 18 +++++++++---------
>  2 files changed, 10 insertions(+), 10 deletions(-)
>

Reviewed-by: Zi Yan <ziy@nvidia.com>


--
Best Regards,
Yan, Zi