Re: [PATCH net-next v6 0/8] net: skb: isolate skb data area allocations into a separate bucket

[Kees Cook <kees@kernel.org>]

On Thu, Oct 08, 2026 at 11:25:13PM +0200, Harry Yoo wrote:
> On Tue, Oct 06, 2026 at 02:20:26AM -0700, Kees Cook wrote:
> > Hi!
> 
> Hi Kees!
> 
> Was hoping to say hi to you at LPC but I missed the chance ;)
> Maybe next time. Safe travels!

Hi! Yes, I kept trying to find you and Vlastimil but it never worked out.
LPC is a non-stop hallway track usually. :) I will try again next year!

> > So v6 goes back to mirroring the kmalloc cache's alignment,
> 
> I might be missing something, but why is that a problem?
> 
> For kmem_buckets users, the reason* to specify alignment is because
> they might need less strict alignment than kmalloc.
> 
> (*Perhaps it's nice to document that in the comment)
> 
> However, because kmem_buckets can fall back to kmalloc on e.g. kernels
> w/o CONFIG_SLAB_BUCKETS, it should be fine to fall back. No?
> 
> Creating kmem_buckets with more strict alignment than
> kmalloc doesn't make sense. 
> 
> > and drops the ctor and flags arguments for the same reason.
> 
> Uh, for ctor and flags, yes. We can't have them in kmem_buckets.

Yeah, and given that these two, I'd just prefer to keep it a direct
mirror for alignment too and not allow for any configurability here:
they are supposed to be direct stand-ins for the general cache.

> Going thorough slab/for-next sounds reasonable to me once it gets
> some reviews.

Thanks!

-Kees

-- 
Kees Cook