Re: [PATCH 1/2] mm: page_alloc: speed up fallbacks in rmqueue_bulk()

[Yunsheng Lin]

On 2025/4/8 2:01, Johannes Weiner wrote:

...

>  
> @@ -2934,6 +2981,7 @@ struct page *rmqueue_buddy(struct zone *preferred_zone, struct zone *zone,
>  {
>  	struct page *page;
>  	unsigned long flags;
> +	enum rmqueue_mode rmqm = RMQUEUE_NORMAL;
>  
>  	do {
>  		page = NULL;
> @@ -2945,7 +2993,7 @@ struct page *rmqueue_buddy(struct zone *preferred_zone, struct zone *zone,
>  		if (alloc_flags & ALLOC_HIGHATOMIC)
>  			page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
>  		if (!page) {
> -			page = __rmqueue(zone, order, migratetype, alloc_flags);
> +			page = __rmqueue(zone, order, migratetype, alloc_flags, &rmqm);
>  
>  			/*
>  			 * If the allocation fails, allow OOM handling and

It was not in the diff, but it seems the zone->lock is held inside the do..while loop,
doesn't it mean that the freelists are subject to outside changes and rmqm is stale?