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Date: Thu, 11 Apr 2024 09:51:13 -0700 (PDT)
From: "Christoph Lameter (Ampere)" <cl@linux.com>
To: Haifeng Xu <haifeng.xu@shopee.com>
cc: vbabka@suse.cz, penberg@kernel.org, rientjes@google.com, 
    iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, 
    roman.gushchin@linux.dev, 42.hyeyoo@gmail.com, linux-mm@kvack.org, 
    linux-kernel@vger.kernel.org
Subject: Re: [PATCH] slub: Clear __GFP_COMP flag when allocating 0 order
 page
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On Thu, 11 Apr 2024, Haifeng Xu wrote:

> @@ -1875,6 +1875,13 @@ static inline struct slab *alloc_slab_page(gfp_t flags, int node,
> 	struct slab *slab;
> 	unsigned int order = oo_order(oo);
>
> +	/*
> +	 * If fallback to the minimum order allocation and the order is 0,
> +	 * clear the __GFP_COMP flag.
> +	 */
> +	if (order == 0)
> +		flags = flags & ~__GFP_COMP;


This would be better placed in allocate_slab() when the need for a
fallback to a lower order is detected after the first call to alloc_slab_page().