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Subject: Re: [PATCH 01/14] mm, compaction: Shrink compact_control
To:     Mel Gorman <mgorman@techsingularity.net>,
        Linux-MM <linux-mm@kvack.org>
Cc:     David Rientjes <rientjes@google.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Michal Hocko <mhocko@kernel.org>, ying.huang@intel.com,
        kirill@shutemov.name, Andrew Morton <akpm@linux-foundation.org>,
        Linux List Kernel Mailing <linux-kernel@vger.kernel.org>
References: <20181214230310.572-1-mgorman@techsingularity.net>
 <20181214230310.572-2-mgorman@techsingularity.net>
From:   Vlastimil Babka <vbabka@suse.cz>
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Date:   Mon, 17 Dec 2018 13:27:20 +0100
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On 12/15/18 12:02 AM, Mel Gorman wrote:
> The isolate and migrate scanners should never isolate more than a pageblock
> of pages so unsigned int is sufficient saving 8 bytes on a 64-bit build.
> 
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> ---
>  mm/internal.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/internal.h b/mm/internal.h
> index 536bc2a839b9..5564841fce36 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -185,8 +185,8 @@ struct compact_control {
>  	struct list_head freepages;	/* List of free pages to migrate to */
>  	struct list_head migratepages;	/* List of pages being migrated */
>  	struct zone *zone;
> -	unsigned long nr_freepages;	/* Number of isolated free pages */
> -	unsigned long nr_migratepages;	/* Number of pages to migrate */
> +	unsigned int nr_freepages;	/* Number of isolated free pages */
> +	unsigned int nr_migratepages;	/* Number of pages to migrate */
>  	unsigned long total_migrate_scanned;
>  	unsigned long total_free_scanned;
>  	unsigned long free_pfn;		/* isolate_freepages search base */
>