Re: [PATCH v4 02/17] mm: introduce kmem_cache_alloc_lru

[Johannes Weiner]

On Tue, Dec 14, 2021 at 12:53:27AM +0800, Muchun Song wrote:
> +/*
> + * The allocated list lru pointers array is not accounted directly.
> + * Moreover, it should not come from DMA buffer and is not readily
> + * reclaimable. So those GFP bits should be masked off.
> + */
> +#define LRUS_CLEAR_MASK	(__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT | __GFP_ZERO)

There is already GFP_RECLAIM_MASK for this purpose, you can use that.

> +int memcg_list_lru_alloc(struct mem_cgroup *memcg, struct list_lru *lru,
> +			 gfp_t gfp)
> +{
> +	int i;
> +	unsigned long flags;
> +	struct list_lru_memcg *mlrus;
> +	struct list_lru_memcg_table {
> +		struct list_lru_per_memcg *mlru;
> +		struct mem_cgroup *memcg;
> +	} *table;
> +
> +	if (!list_lru_memcg_aware(lru) || memcg_list_lru_allocated(memcg, lru))
> +		return 0;
> +
> +	gfp &= ~LRUS_CLEAR_MASK;

	gfp &= GFP_RECLAIM_MASK;