Re: [PATCH] mm: change size_t to unsigned int for cma_alloc

[Matthew Wilcox <willy@infradead.org>]

On Mon, Mar 29, 2021 at 11:25:53AM -0700, Minchan Kim wrote:
> size_t in cma_alloc is confusing since it makes people think
> it's byte count, not pages. Fix it.

i think it has to be unsigned long.

67a2e213e7e937c41c52ab5bc46bf3f4de469f6e

> Link: https://lore.kernel.org/linux-mm/20210324043434.GP1719932@casper.infradead.org/
> Cc: Matthew Wilcox <willy@infradead.org>
> Signed-off-by: Minchan Kim <minchan@kernel.org>
> ---
>  include/linux/cma.h | 2 +-
>  mm/cma.c            | 8 ++++----
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/cma.h b/include/linux/cma.h
> index 217999c8a762..a873edc20ca2 100644
> --- a/include/linux/cma.h
> +++ b/include/linux/cma.h
> @@ -44,7 +44,7 @@ extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
>  					unsigned int order_per_bit,
>  					const char *name,
>  					struct cma **res_cma);
> -extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
> +extern struct page *cma_alloc(struct cma *cma, unsigned int count, unsigned int align,
>  			      bool no_warn);
>  extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count);
>  
> diff --git a/mm/cma.c b/mm/cma.c
> index 08c45157911a..24dc01e26d45 100644
> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -423,21 +423,21 @@ static inline void cma_debug_show_areas(struct cma *cma) { }
>   * This function allocates part of contiguous memory on specific
>   * contiguous memory area.
>   */
> -struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
> +struct page *cma_alloc(struct cma *cma, unsigned int count, unsigned int align,
>  		       bool no_warn)
>  {
>  	unsigned long mask, offset;
>  	unsigned long pfn = -1;
>  	unsigned long start = 0;
>  	unsigned long bitmap_maxno, bitmap_no, bitmap_count;
> -	size_t i;
> +	unsigned int i;
>  	struct page *page = NULL;
>  	int ret = -ENOMEM;
>  
>  	if (!cma || !cma->count || !cma->bitmap)
>  		goto out;
>  
> -	pr_debug("%s(cma %p, count %zu, align %d)\n", __func__, (void *)cma,
> +	pr_debug("%s(cma %p, count %u, align %d)\n", __func__, (void *)cma,
>  		 count, align);
>  
>  	if (!count)
> @@ -500,7 +500,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
>  	}
>  
>  	if (ret && !no_warn) {
> -		pr_err_ratelimited("%s: %s: alloc failed, req-size: %zu pages, ret: %d\n",
> +		pr_err_ratelimited("%s: %s: alloc failed, req-size: %u pages, ret: %d\n",
>  				   __func__, cma->name, count, ret);
>  		cma_debug_show_areas(cma);
>  	}
> -- 
> 2.31.0.291.g576ba9dcdaf-goog
> 
>