Re: [PATCH RFC 03/19] slub: remove CONFIG_SLUB_TINY specific code paths

From: Vlastimil Babka

Date: Wed Oct 29 2025 - 11:37:23 EST


On 10/25/25 00:34, Alexei Starovoitov wrote:
> On Thu, Oct 23, 2025 at 6:53 AM Vlastimil Babka <vbabka@xxxxxxx> wrote:
>>
>> CONFIG_SLUB_TINY minimizes the SLUB's memory overhead in multiple ways,
>> mainly by avoiding percpu caching of slabs and objects. It also reduces
>> code size by replacing some code paths with simplified ones through
>> ifdefs, but the benefits of that are smaller and would complicate the
>> upcoming changes.
>>
>> Thus remove these code paths and associated ifdefs and simplify the code
>> base.
>>
>> Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
>> ---
>> mm/slab.h | 2 --
>> mm/slub.c | 107 +++-----------------------------------------------------------
>> 2 files changed, 4 insertions(+), 105 deletions(-)
>
> Looks like it is removing most of it.

The special code, yes. But the savings from avoiding percpu caching are the
most important anyway and they stay.

> Just remove the whole thing. Do people care about keeping SLUB_TINY?

They did when SLOB was being removed. We can always remove it completely
later, but this code cleanup is enough for me not to complicate the further
changes, so I wouldn't want to put the complete removal in this series.