On Wed, May 29, 2024 at 08:00:41PM +0200, Bernd Schubert wrote:
> This is to have a numa aware vmalloc function for memory exposed to
> userspace. Fuse uring will allocate queue memory using this
> new function.
>
> Signed-off-by: Bernd Schubert <bschubert@xxxxxxx>
> cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> cc: linux-mm@xxxxxxxxx
> Acked-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> ---
> include/linux/vmalloc.h | 1 +
> mm/nommu.c | 6 ++++++
> mm/vmalloc.c | 41 +++++++++++++++++++++++++++++++++++++----
> 3 files changed, 44 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
> index 98ea90e90439..e7645702074e 100644
> --- a/include/linux/vmalloc.h
> +++ b/include/linux/vmalloc.h
> @@ -141,6 +141,7 @@ static inline unsigned long vmalloc_nr_pages(void) { return 0; }
> extern void *vmalloc(unsigned long size) __alloc_size(1);
> extern void *vzalloc(unsigned long size) __alloc_size(1);
> extern void *vmalloc_user(unsigned long size) __alloc_size(1);
> +extern void *vmalloc_node_user(unsigned long size, int node) __alloc_size(1);
> extern void *vmalloc_node(unsigned long size, int node) __alloc_size(1);
> extern void *vzalloc_node(unsigned long size, int node) __alloc_size(1);
> extern void *vmalloc_32(unsigned long size) __alloc_size(1);
> diff --git a/mm/nommu.c b/mm/nommu.c
> index 5ec8f44e7ce9..207ddf639aa9 100644
> --- a/mm/nommu.c
> +++ b/mm/nommu.c
> @@ -185,6 +185,12 @@ void *vmalloc_user(unsigned long size)
> }
> EXPORT_SYMBOL(vmalloc_user);
>
> +void *vmalloc_node_user(unsigned long size, int node)
> +{
> + return __vmalloc_user_flags(size, GFP_KERNEL | __GFP_ZERO);
> +}
> +EXPORT_SYMBOL(vmalloc_node_user);
> +
> struct page *vmalloc_to_page(const void *addr)
> {
> return virt_to_page(addr);
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 68fa001648cc..0ac2f44b2b1f 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -3958,6 +3958,25 @@ void *vzalloc(unsigned long size)
> }
> EXPORT_SYMBOL(vzalloc);
>
> +/**
> + * _vmalloc_node_user - allocate zeroed virtually contiguous memory for userspace
Please avoid the overly long line.
> + * on the given numa node
> + * @size: allocation size
> + * @node: numa node
> + *
> + * The resulting memory area is zeroed so it can be mapped to userspace
> + * without leaking data.
> + *
> + * Return: pointer to the allocated memory or %NULL on error
> + */
> +static void *_vmalloc_node_user(unsigned long size, int node)
Although for static functions kerneldoc comments are pretty silly
to start with.
> void *vmalloc_user(unsigned long size)
> {
> - return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
> - GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
> - VM_USERMAP, NUMA_NO_NODE,
> - __builtin_return_address(0));
> + return _vmalloc_node_user(size, NUMA_NO_NODE);
But I suspect simply adding a gfp_t argument to vmalloc_node might be
a much easier to use interface here, even if it would need a sanity
check to only allow for actually useful to vmalloc flags.
