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Date:   Sun, 21 Aug 2022 12:44:16 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Michal Hocko <mhocko@suse.com>
Cc:     Christoph Hellwig <hch@lst.de>, iommu@lists.linux.dev,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Robin Murphy <robin.murphy@arm.com>,
        David Rientjes <rientjes@google.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/3] dma-pool: limit DMA and DMA32 zone size pools
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On Wed, Aug 17, 2022 at 02:53:47PM +0200, Michal Hocko wrote:
> Yes this is much more reasonable estimation. Especially for the DMA
> zone. I still believe some downscaling would make sense but as said
> earlier nothing to really insist on. Also you likely want to have
> pr_warn for non-poppulated DMA zone as pointed in other thread[1].

So I think the warning would be useful, but how do we detect that the
zone should exist and is empty vs the case where it doesn't even
exist based on a runtime decision?