Re: [PATCH 1/4] mm/vmalloc: Remove unnecessary size ALIGN in __vmalloc_node_range_noprof

[Uladzislau Rezki]

On Mon, Mar 03, 2025 at 05:44:07PM +0800, Liu Ye wrote:
> The same operation already exists in the function __get_vm_area_node,
> so delete the duplicate operation to simplify the code.
> 
> Signed-off-by: Liu Ye <liuye@xxxxxxxxxx>
> ---
>  mm/vmalloc.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index dc658d4af181..20d9b9de84b1 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -3798,7 +3798,6 @@ void *__vmalloc_node_range_noprof(unsigned long size, unsigned long align,
>  			shift = arch_vmap_pte_supported_shift(size);
>  
>  		align = max(real_align, 1UL << shift);
> -		size = ALIGN(real_size, 1UL << shift);
>  	}
>  
>  again:
> -- 
> 2.25.1
> 
There is a mess with:

 unsigned long real_size = size;
 unsigned long real_align = align;

"real_size" and "real_align". Those are useless. What is about:

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 5c88d0e90c20..a381ffee1595 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -3771,8 +3771,6 @@ void *__vmalloc_node_range_noprof(unsigned long size, unsigned long align,
 	struct vm_struct *area;
 	void *ret;
 	kasan_vmalloc_flags_t kasan_flags = KASAN_VMALLOC_NONE;
-	unsigned long real_size = size;
-	unsigned long real_align = align;
 	unsigned int shift = PAGE_SHIFT;
 
 	if (WARN_ON_ONCE(!size))
@@ -3781,7 +3779,7 @@ void *__vmalloc_node_range_noprof(unsigned long size, unsigned long align,
 	if ((size >> PAGE_SHIFT) > totalram_pages()) {
 		warn_alloc(gfp_mask, NULL,
 			"vmalloc error: size %lu, exceeds total pages",
-			real_size);
+			size);
 		return NULL;
 	}
 
@@ -3798,19 +3796,18 @@ void *__vmalloc_node_range_noprof(unsigned long size, unsigned long align,
 		else
 			shift = arch_vmap_pte_supported_shift(size);
 
-		align = max(real_align, 1UL << shift);
-		size = ALIGN(real_size, 1UL << shift);
+		align = max(align, 1UL << shift);
 	}
 
 again:
-	area = __get_vm_area_node(real_size, align, shift, VM_ALLOC |
+	area = __get_vm_area_node(size, align, shift, VM_ALLOC |
 				  VM_UNINITIALIZED | vm_flags, start, end, node,
 				  gfp_mask, caller);
 	if (!area) {
 		bool nofail = gfp_mask & __GFP_NOFAIL;
 		warn_alloc(gfp_mask, NULL,
 			"vmalloc error: size %lu, vm_struct allocation failed%s",
-			real_size, (nofail) ? ". Retrying." : "");
+			size, (nofail) ? ". Retrying." : "");
 		if (nofail) {
 			schedule_timeout_uninterruptible(1);
 			goto again;
@@ -3860,7 +3857,7 @@ void *__vmalloc_node_range_noprof(unsigned long size, unsigned long align,
 	    (gfp_mask & __GFP_SKIP_ZERO))
 		kasan_flags |= KASAN_VMALLOC_INIT;
 	/* KASAN_VMALLOC_PROT_NORMAL already set if required. */
-	area->addr = kasan_unpoison_vmalloc(area->addr, real_size, kasan_flags);
+	area->addr = kasan_unpoison_vmalloc(area->addr, size, kasan_flags);
 
 	/*
 	 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
@@ -3878,8 +3875,6 @@ void *__vmalloc_node_range_noprof(unsigned long size, unsigned long align,
 fail:
 	if (shift > PAGE_SHIFT) {
 		shift = PAGE_SHIFT;
-		align = real_align;
-		size = real_size;
 		goto again;
 	}
 
?

--
Uladzislau Rezki