Re: [PATCH v4 03/36] mm/slub: Mark slab_free_freelist_hook() __always_inline

Vlastimil Babka
2024-02-26T14:31:38Z

On 2/24/24 03:02, Suren Baghdasaryan wrote:
> On Wed, Feb 21, 2024 at 1:16 PM Pasha Tatashin
> <pasha.tatashin@soleen.com> wrote:
>>
>> On Wed, Feb 21, 2024 at 2:41 PM Suren Baghdasaryan <surenb@google.com> wrote:
>> >
>> > From: Kent Overstreet <kent.overstreet@linux.dev>
>> >
>> > It seems we need to be more forceful with the compiler on this one.
>> > This is done for performance reasons only.
>> >
>> > Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
>> > Signed-off-by: Suren Baghdasaryan <surenb@google.com>
>> > Reviewed-by: Kees Cook <keescook@chromium.org>
>> > ---
>> > mm/slub.c | 2 +-
>> > 1 file changed, 1 insertion(+), 1 deletion(-)
>> >
>> > diff --git a/mm/slub.c b/mm/slub.c
>> > index 2ef88bbf56a3..d31b03a8d9d5 100644
>> > --- a/mm/slub.c
>> > +++ b/mm/slub.c
>> > @@ -2121,7 +2121,7 @@ bool slab_free_hook(struct kmem_cache *s, void *x, bool init)
>> > return !kasan_slab_free(s, x, init);
>> > }
>> >
>> > -static inline bool slab_free_freelist_hook(struct kmem_cache *s,
>> > +static __always_inline bool slab_free_freelist_hook(struct kmem_cache *s,
>>
>> __fastpath_inline seems to me more appropriate here. It prioritizes
>> memory vs performance.
>
> Hmm. AFAIKT this function is used only in one place and we do not add
> any additional users, so I don't think changing to __fastpath_inline
> here would gain us anything.

It would have been more future-proof and self-documenting. But I don't insist.

Reviewed-by: Vlastimil Babka <vbabka@suse.cz>

>>
>> > void **head, void **tail,
>> > int *cnt)
>> > {
>> > --
>> > 2.44.0.rc0.258.g7320e95886-goog
>> >