Re: [PATCH] CMA: call to putback_lru_pages

[Michal Nazarewicz <mina86@mina86.com>]

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[+marek]

On Mon, Dec 17 2012, Srinivas Pandruvada wrote:
> As per documentation and other places calling putback_lru_pages,
> on error only, except for CMA. I am not sure this is a problem
> for CMA or not.

If ret >= 0 than the list is empty anyway so the effect of this patch is
to save a function call.  It's also true that other callers call it only
on error so __alloc_contig_migrate_range() is an odd man out here.  As
such:

Acked-by: Michal Nazarewicz <mina86@mina86.com>

> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> ---
>  mm/page_alloc.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 83637df..5a887bf 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5802,8 +5802,8 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
>  				    alloc_migrate_target,
>  				    0, false, MIGRATE_SYNC);
>  	}
> -
> -	putback_movable_pages(&cc->migratepages);
> +	if (ret < 0)
> +		putback_movable_pages(&cc->migratepages);
>  	return ret > 0 ? 0 : ret;
>  }

-- 
Best regards,                                         _     _
.o. | Liege of Serenely Enlightened Majesty of      o' \,=./ `o
..o | Computer Science,  Michał “mina86” Nazarewicz    (o o)
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