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Hello, Helmut. |
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On Mon, Feb 04, 2019 at 12:01:33 +0100, Helmut Jarausch wrote: |
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> I have a very fast Samsung NVME drive hosting my root file system. |
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> During backup 'atop' often shows 100% usage of my NVME drive while |
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> reading only a few MB/s and |
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> several thousands 'Read' ops (during 10 seconds). |
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> Is this normal or a measuring bug of 'atop'. |
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> Stand alone timing tests have shown that this drive can read some GB |
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> per second. |
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> What's happening? |
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I don't understand this well myself, but please make sure you've got |
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CONFIG_PCI_MSI ("message signalled interrupts") enabled in your kernel. |
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This was a tip from Adam Carter to me in 2017-04, when my new Samsung |
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NVMe drive wasn't performing to expectations, and it helped greatly. |
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> Many thanks for a hint, |
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> Helmut |
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-- |
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Alan Mackenzie (Nuremberg, Germany). |
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