Re: [PATCH] mm: delete bool "migrated"

[Andrew Morton]

On Mon,  1 Mar 2021 20:57:01 +0800 Wang Qing <wangqing@xxxxxxxx> wrote:

> Smatch gives the warning:
> 	do_numa_page() warn: assigning (-11) to unsigned variable 'migrated'
> 
> ...
>
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -4102,7 +4102,6 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf)
>  	int page_nid = NUMA_NO_NODE;
>  	int last_cpupid;
>  	int target_nid;
> -	bool migrated = false;
>  	pte_t pte, old_pte;
>  	bool was_writable = pte_savedwrite(vmf->orig_pte);
>  	int flags = 0;
> @@ -4172,8 +4171,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf)
>  	}
>  
>  	/* Migrate to the requested node */
> -	migrated = migrate_misplaced_page(page, vma, target_nid);
> -	if (migrated) {
> +	if (migrate_misplaced_page(page, vma, target_nid)) {
>  		page_nid = target_nid;
>  		flags |= TNF_MIGRATED;
>  	} else

Looks right.

Methinks both migrate_misplaced_page() and numamigrate_isolate_page()
should return bools.  (And that their return values should be documented!)