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Date:   Fri, 12 Mar 2021 09:29:38 +0000
From:   Christoph Hellwig <hch@infradead.org>
To:     Jianqun Xu <jay.xu@rock-chips.com>
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Subject: Re: [PATCH] mm/slab: kmalloc with GFP_DMA32 allocate from
 SLAB_CACHE_DMA32
Message-ID: <20210312092938.GA2412021@infradead.org>
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On Fri, Mar 12, 2021 at 04:03:20PM +0800, Jianqun Xu wrote:
> The flag GFP_DMA32 only effect in kmalloc_large currently.
> 
> This patch will create caches with GFP_DMA32 to support kmalloc with
> size under KMALLOC_MAX_CACHE_SIZE.

No.  No new code should use GFP_DMA32, never mind through slab.
Please use the proper DMA APIs for your addressing needs.