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Date:   Fri, 9 Jul 2021 11:16:14 +0100
From:   "Russell King (Oracle)" <linux@armlinux.org.uk>
To:     Ming Lei <ming.lei@redhat.com>
Cc:     linux-nvme@lists.infradead.org, Will Deacon <will@kernel.org>,
        linux-arm-kernel@lists.infradead.org,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [bug report] iommu_dma_unmap_sg() is very slow then running IO
 from remote numa node
Message-ID: <20210709101614.GZ22278@shell.armlinux.org.uk>
References: <YOgK8fdv7dOQtkET@T590>
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Sender: Russell King (Oracle) <linux@armlinux.org.uk>
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On Fri, Jul 09, 2021 at 04:38:09PM +0800, Ming Lei wrote:
> I observed that NVMe performance is very bad when running fio on one
> CPU(aarch64) in remote numa node compared with the nvme pci numa node.

Have you checked the effect of running a memory-heavy process using
memory from node 1 while being executed by CPUs in node 0?

-- 
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