Re: [PATCH net-next v1] neighbour: Replace kvzalloc() with kzalloc() when GFP_ATOMIC is specified

Eric Dumazet
2025-02-17T08:56:18Z

On Sun, Feb 16, 2025 at 8:07 PM Kuniyuki Iwashima <kuniyu@amazon.com> wrote:
>
> From: Kohei Enju <enjuk@amazon.com>
> Date: Mon, 17 Feb 2025 01:30:16 +0900
> > Replace kvzalloc()/kvfree() with kzalloc()/kfree() when GFP_ATOMIC is
> > specified, since kvzalloc() doesn't support non-sleeping allocations such
> > as GFP_ATOMIC.
> >
> > With incompatible gfp flags, kvzalloc() never falls back to the vmalloc
> > path and returns immediately after the kmalloc path fails.
> > Therefore, using kzalloc() is sufficient in this case.
> >
> > Fixes: 41b3caa7c076 ("neighbour: Add hlist_node to struct neighbour")
>
> This commit followed the old hash_buckets allocation, so I'd add
>
> Fixes: ab101c553bc1 ("neighbour: use kvzalloc()/kvfree()")
>
> too.
>
> Both commits were introduced in v6.13, so there's no difference in terms
> of backporting though.
>
> Also, it would be nice to CC mm maintainers in case they have some
> comments.

Oh well, we need to trigger neigh_hash_grow() from a process context,
or convert net/core/neighbour.c to modern rhashtable.