Re: [PATCH v5 2/5] mm,compaction: Let isolate_migratepages_{range,block} return error codes

[Oscar Salvador]

On Fri, Mar 19, 2021 at 11:14:25AM +0100, Vlastimil Babka wrote:
> No I meant this:
> 
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -225,7 +225,13 @@ struct compact_control {
>         unsigned int nr_freepages;      /* Number of isolated free pages */
>         unsigned int nr_migratepages;   /* Number of pages to migrate */
>         unsigned long free_pfn;         /* isolate_freepages search base */
> -       unsigned long migrate_pfn;      /* isolate_migratepages search base */
> +       /*
> +        * Acts as an in/out parameter to page isolation for migration.
> +        * isolate_migratepages uses it as a search base.
> +        * isolate_migratepages_block will update the value to the next pfn
> +        * after the last isolated one.
> +        */
> +       unsigned long migrate_pfn;
>         unsigned long fast_start_pfn;   /* a pfn to start linear scan from */
>         struct zone *zone;
>         unsigned long total_migrate_scanned;

Meh, silly me.
Ok, I will do it that way.

I am also for expanding some of the comments as I see that some explanations are
rather laconic, but I do not think such work fits in this patchset.

Since I happen to be checking compaction code due to other reasons, I shall
come back to this matter once I am done with this patchset.

-- 
Oscar Salvador
SUSE L3