Re: [PATCH v6 2/8] mm: vmalloc: don't account for number of nodes for HUGE_VMAP allocations

Luis Chamberlain
2024-10-19T22:19:28Z

On Wed, Oct 16, 2024 at 03:24:18PM +0300, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
>
> vmalloc allocations with VM_ALLOW_HUGE_VMAP that do not explicitly
> specify node ID will use huge pages only if size_per_node is larger than
> a huge page.
> Still the actual allocated memory is not distributed between nodes and
> there is no advantage in such approach.
> On the contrary, BPF allocates SZ_2M * num_possible_nodes() for each
> new bpf_prog_pack, while it could do with a single huge page per pack.
>
> Don't account for number of nodes for VM_ALLOW_HUGE_VMAP with
> NUMA_NO_NODE and use huge pages whenever the requested allocation size
> is larger than a huge page.
>
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>

Luis