Re: [PATCH 3/5] mm/slab: Do not call kmalloc_large() for unsupported size

[Hyeonggon Yoo]

On Mon, Feb 21, 2022 at 03:53:39PM +0000, Matthew Wilcox wrote:
> On Mon, Feb 21, 2022 at 10:53:34AM +0000, Hyeonggon Yoo wrote:
> > SLAB's kfree() does not support freeing an object that is allocated from
> > kmalloc_large(). Fix this as SLAB do not pass requests larger than
> > KMALLOC_MAX_CACHE_SIZE directly to page allocator.
> 
> I was wondering if we wanted to go in the other direction and get rid of
> kmalloc cache sizes larger than, say, 64kB from the SLAB allocator.

Good point.

Hmm.. I don't think SLAB is benefiting from queueing that large objects,
and maximum size is still limited to what buddy allocator supports.

I'll try reducing kmalloc caches up to order-1 page like SLUB.
That would be easier to maintain.

Thanks,
Hyeonggon