Re: [PATCH v3 14/16] mm: Move __alloc_pages() to mm/page_alloc.h

["Vlastimil Babka (SUSE)" <vbabka@kernel.org>]

On 6/29/26 15:12, Brendan Jackman wrote:
> It's no longer used outside of mm/.
> 
> Since this means __alloc_pages_noprof() is no longer visible from gfp.h,
> this also means moving the definition of alloc_pages_node_noprof into
> the .c file.
> 
> Also remove references to this API from the documentation tree -
> referring to the specific function name was already questionable but
> now the function is not even public it definitely seems wrong.
> 
> Signed-off-by: Brendan Jackman <jackmanb@google.com>

Less inline bloat also good.

Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>

> ---
>  Documentation/admin-guide/cgroup-v1/cpusets.rst |  2 +-
>  Documentation/admin-guide/mm/transhuge.rst      |  2 +-
>  include/linux/gfp.h                             | 16 +---------------
>  mm/page_alloc.c                                 | 13 ++++++++++++-
>  mm/page_alloc.h                                 |  4 ++++
>  5 files changed, 19 insertions(+), 18 deletions(-)
> 
> diff --git a/Documentation/admin-guide/cgroup-v1/cpusets.rst b/Documentation/admin-guide/cgroup-v1/cpusets.rst
> index c7909e5ac1361..52a213aff04e5 100644
> --- a/Documentation/admin-guide/cgroup-v1/cpusets.rst
> +++ b/Documentation/admin-guide/cgroup-v1/cpusets.rst
> @@ -284,7 +284,7 @@ take action.
>  ==>
>      Unless this feature is enabled by writing "1" to the special file
>      /dev/cpuset/memory_pressure_enabled, the hook in the rebalance
> -    code of __alloc_pages() for this metric reduces to simply noticing
> +    code of the page allocator for this metric reduces to simply noticing
>      that the cpuset_memory_pressure_enabled flag is zero.  So only
>      systems that enable this feature will compute the metric.
>  
> diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
> index 23f8d13c2629d..16f37135ed80d 100644
> --- a/Documentation/admin-guide/mm/transhuge.rst
> +++ b/Documentation/admin-guide/mm/transhuge.rst
> @@ -761,7 +761,7 @@ compact_fail
>  	but failed.
>  
>  It is possible to establish how long the stalls were using the function
> -tracer to record how long was spent in __alloc_pages() and
> +tracer to record how long was spent in the page allocator and
>  using the mm_page_alloc tracepoint to identify which allocations were
>  for huge pages.
>  
> diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> index 3bf55a5f9143e..4d57e9c0bf204 100644
> --- a/include/linux/gfp.h
> +++ b/include/linux/gfp.h
> @@ -204,10 +204,6 @@ static inline void arch_free_page(struct page *page, int order) { }
>  static inline void arch_alloc_page(struct page *page, int order) { }
>  #endif
>  
> -struct page *__alloc_pages_noprof(gfp_t gfp, unsigned int order, int preferred_nid,
> -		nodemask_t *nodemask);
> -#define __alloc_pages(...)			alloc_hooks(__alloc_pages_noprof(__VA_ARGS__))
> -
>  struct folio *__folio_alloc_noprof(gfp_t gfp, unsigned int order, int preferred_nid,
>  		nodemask_t *nodemask);
>  #define __folio_alloc(...)			alloc_hooks(__folio_alloc_noprof(__VA_ARGS__))
> @@ -272,17 +268,7 @@ struct folio *__folio_alloc_node_noprof(gfp_t gfp, unsigned int order, int nid)
>   * prefer the current CPU's closest node. Otherwise node must be valid and
>   * online.
>   */
> -static inline struct page *alloc_pages_node_noprof(int nid, gfp_t gfp_mask,
> -						   unsigned int order)
> -{
> -	if (nid == NUMA_NO_NODE)
> -		nid = numa_mem_id();
> -
> -	VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
> -	warn_if_node_offline(nid, gfp_mask);
> -
> -	return __alloc_pages_noprof(gfp_mask, order, nid, NULL);
> -}
> +struct page *alloc_pages_node_noprof(int nid, gfp_t gfp_mask, unsigned int order);
>  
>  #define  alloc_pages_node(...)			alloc_hooks(alloc_pages_node_noprof(__VA_ARGS__))
>  
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 9cb3f1665b41b..026f33f217036 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5427,7 +5427,18 @@ struct page *__alloc_pages_noprof(gfp_t gfp, unsigned int order,
>  		set_page_refcounted(page);
>  	return page;
>  }
> -EXPORT_SYMBOL(__alloc_pages_noprof);
> +
> +struct page *alloc_pages_node_noprof(int nid, gfp_t gfp_mask, unsigned int order)
> +{
> +	if (nid == NUMA_NO_NODE)
> +		nid = numa_mem_id();
> +
> +	VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
> +	warn_if_node_offline(nid, gfp_mask);
> +
> +	return __alloc_pages_noprof(gfp_mask, order, nid, NULL);
> +}
> +EXPORT_SYMBOL(alloc_pages_node_noprof);
>  
>  struct folio *__folio_alloc_noprof(gfp_t gfp, unsigned int order, int preferred_nid,
>  		nodemask_t *nodemask)
> diff --git a/mm/page_alloc.h b/mm/page_alloc.h
> index af83764788b96..2058cbdca56e7 100644
> --- a/mm/page_alloc.h
> +++ b/mm/page_alloc.h
> @@ -244,6 +244,10 @@ struct page *alloc_frozen_pages_nolock_noprof(gfp_t gfp_flags, int nid, unsigned
>  	alloc_hooks(alloc_frozen_pages_nolock_noprof(__VA_ARGS__))
>  void free_frozen_pages_nolock(struct page *page, unsigned int order);
>  
> +struct page *__alloc_pages_noprof(gfp_t gfp, unsigned int order, int preferred_nid,
> +		nodemask_t *nodemask);
> +#define __alloc_pages(...)			alloc_hooks(__alloc_pages_noprof(__VA_ARGS__))
> +
>  extern void zone_pcp_reset(struct zone *zone);
>  extern void zone_pcp_disable(struct zone *zone);
>  extern void zone_pcp_enable(struct zone *zone);
>