Re: [PATCH 1/2] mm: cma: NUMA node interface

[Michal Hocko <mhocko@kernel.org>]

On Thu 26-03-20 14:27:17, Aslan Bakirov wrote:
> I've noticed that there is no interfaces exposed by CMA which would let me
> to declare contigous memory on particular NUMA node.
> 
> This patchset adds the ability to try to allocate contiguous memory on
> specific node.
> 
> Implement a new method for declaring contigous memory on particular node
> and keep cma_declare_contiguous() as a wrapper.

I am not an expert on CMA but this looks very reasonable to me.

> Signed-off-by: Aslan Bakirov <aslan@fb.com>
> ---
>  include/linux/cma.h      | 14 ++++++++++++--
>  include/linux/memblock.h |  3 +++
>  mm/cma.c                 | 15 ++++++++-------
>  mm/memblock.c            |  2 +-
>  4 files changed, 24 insertions(+), 10 deletions(-)
> 
> diff --git a/include/linux/cma.h b/include/linux/cma.h
> index 190184b5ff32..9512229744e0 100644
> --- a/include/linux/cma.h
> +++ b/include/linux/cma.h
> @@ -24,10 +24,20 @@ extern phys_addr_t cma_get_base(const struct cma *cma);
>  extern unsigned long cma_get_size(const struct cma *cma);
>  extern const char *cma_get_name(const struct cma *cma);
>  
> -extern int __init cma_declare_contiguous(phys_addr_t base,
> +extern int __init cma_declare_contiguous_nid(phys_addr_t base,
>  			phys_addr_t size, phys_addr_t limit,
>  			phys_addr_t alignment, unsigned int order_per_bit,
> -			bool fixed, const char *name, struct cma **res_cma);
> +			bool fixed, const char *name, struct cma **res_cma,
> +			int nid);
> +static inline int __init cma_declare_contiguous(phys_addr_t base,
> +			phys_addr_t size, phys_addr_t limit,
> +			phys_addr_t alignment, unsigned int order_per_bit,
> +			bool fixed, const char *name, struct cma **res_cma)
> +			{
> +				return cma_declare_contiguous_nid(base, size,
> +						limit, alignment, order_per_bit,
> +						fixed, name, res_cma, NUMA_NO_NODE);
> +			}
>  extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
>  					unsigned int order_per_bit,
>  					const char *name,
> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index 079d17d96410..f5878ed25e6e 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -348,6 +348,9 @@ static inline int memblock_get_region_node(const struct memblock_region *r)
>  
>  phys_addr_t memblock_phys_alloc_range(phys_addr_t size, phys_addr_t align,
>  				      phys_addr_t start, phys_addr_t end);
> +phys_addr_t memblock_alloc_range_nid(phys_addr_t size,
> +					  phys_addr_t align, phys_addr_t start,
> +					  phys_addr_t end, int nid, bool exact_nid);
>  phys_addr_t memblock_phys_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid);
>  
>  static inline phys_addr_t memblock_phys_alloc(phys_addr_t size,
> diff --git a/mm/cma.c b/mm/cma.c
> index be55d1988c67..2300669b4253 100644
> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -220,7 +220,7 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
>  }
>  
>  /**
> - * cma_declare_contiguous() - reserve custom contiguous area
> + * cma_declare_contiguous_nid() - reserve custom contiguous area
>   * @base: Base address of the reserved area optional, use 0 for any
>   * @size: Size of the reserved area (in bytes),
>   * @limit: End address of the reserved memory (optional, 0 for any).
> @@ -229,6 +229,7 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
>   * @fixed: hint about where to place the reserved area
>   * @name: The name of the area. See function cma_init_reserved_mem()
>   * @res_cma: Pointer to store the created cma region.
> + * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
>   *
>   * This function reserves memory from early allocator. It should be
>   * called by arch specific code once the early allocator (memblock or bootmem)
> @@ -238,10 +239,10 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
>   * If @fixed is true, reserve contiguous area at exactly @base.  If false,
>   * reserve in range from @base to @limit.
>   */
> -int __init cma_declare_contiguous(phys_addr_t base,
> +int __init cma_declare_contiguous_nid(phys_addr_t base,
>  			phys_addr_t size, phys_addr_t limit,
>  			phys_addr_t alignment, unsigned int order_per_bit,
> -			bool fixed, const char *name, struct cma **res_cma)
> +			bool fixed, const char *name, struct cma **res_cma, int nid)
>  {
>  	phys_addr_t memblock_end = memblock_end_of_DRAM();
>  	phys_addr_t highmem_start;
> @@ -336,14 +337,14 @@ int __init cma_declare_contiguous(phys_addr_t base,
>  		 * memory in case of failure.
>  		 */
>  		if (base < highmem_start && limit > highmem_start) {
> -			addr = memblock_phys_alloc_range(size, alignment,
> -							 highmem_start, limit);
> +			addr = memblock_alloc_range_nid(size, alignment,
> +							 highmem_start, limit, nid, false);
>  			limit = highmem_start;
>  		}
>  
>  		if (!addr) {
> -			addr = memblock_phys_alloc_range(size, alignment, base,
> -							 limit);
> +			addr = memblock_alloc_range_nid(size, alignment, base,
> +							 limit, nid, false);
>  			if (!addr) {
>  				ret = -ENOMEM;
>  				goto err;
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 4d06bbaded0f..c79ba6f9920c 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -1349,7 +1349,7 @@ __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone,
>   * Return:
>   * Physical address of allocated memory block on success, %0 on failure.
>   */
> -static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
> +phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
>  					phys_addr_t align, phys_addr_t start,
>  					phys_addr_t end, int nid,
>  					bool exact_nid)
> -- 
> 2.17.1

-- 
Michal Hocko
SUSE Labs