Re: [PATCH v5 3/4] mm/page_alloc: move freepage counting logic to __free_one_page()

[Vlastimil Babka]

On 10/31/2014 08:25 AM, Joonsoo Kim wrote:
> All the caller of __free_one_page() has similar freepage counting logic,
> so we can move it to __free_one_page(). This reduce line of code and help
> future maintenance. This is also preparation step for "mm/page_alloc:
> restrict max order of merging on isolated pageblock" which fix the
> freepage counting problem on freepage with more than pageblock order.
>
> Changes from v4:
> Only freepage counting logic is moved. Others remains as is.
>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

Looks like most of the cleanup was still possible, especially getting 
rid of the skip_counting labels is nice.

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>

> ---
>   mm/page_alloc.c |   14 +++-----------
>   1 file changed, 3 insertions(+), 11 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 6df23fe..2bc7768 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -579,6 +579,8 @@ static inline void __free_one_page(struct page *page,
>   			return;
>
>   	VM_BUG_ON(migratetype == -1);
> +	if (!is_migrate_isolate(migratetype))
> +		__mod_zone_freepage_state(zone, 1 << order, migratetype);
>
>   	page_idx = pfn & ((1 << MAX_ORDER) - 1);
>
> @@ -725,14 +727,9 @@ static void free_pcppages_bulk(struct zone *zone, int count,
>   			/* must delete as __free_one_page list manipulates */
>   			list_del(&page->lru);
>   			mt = get_freepage_migratetype(page);
> -			if (unlikely(has_isolate_pageblock(zone))) {
> +			if (unlikely(has_isolate_pageblock(zone)))
>   				mt = get_pageblock_migratetype(page);
> -				if (is_migrate_isolate(mt))
> -					goto skip_counting;
> -			}
> -			__mod_zone_freepage_state(zone, 1, mt);
>
> -skip_counting:
>   			/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
>   			__free_one_page(page, page_to_pfn(page), zone, 0, mt);
>   			trace_mm_page_pcpu_drain(page, 0, mt);
> @@ -755,12 +752,7 @@ static void free_one_page(struct zone *zone,
>   	if (unlikely(has_isolate_pageblock(zone) ||
>   		is_migrate_isolate(migratetype))) {
>   		migratetype = get_pfnblock_migratetype(page, pfn);
> -		if (is_migrate_isolate(migratetype))
> -			goto skip_counting;
>   	}
> -	__mod_zone_freepage_state(zone, 1 << order, migratetype);
> -
> -skip_counting:
>   	__free_one_page(page, pfn, zone, order, migratetype);
>   	spin_unlock(&zone->lock);
>   }

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