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Am 09.03.2013 19:15, schrieb Florian Philipp: |
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> Hi list! |
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> |
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> Whenever I do sequential IO for a long stretch of time (e.g. md5summing |
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> 40 GB), I'm experiencing high load (ca. 6 on a 4 CPU system) and |
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> temporary freezes of most applications. For example, switching between |
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> tabs in konsole sometimes takes more than 2 seconds. |
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> |
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> When doing this on an ext4 filesystem, the load seems to result from |
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> khugepaged and kswapd0 as well as some kworkers. |
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> |
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> I think I've had similar issues with NFS over wifi but I cannot test |
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> this now. |
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> |
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> Today I copied 60GB from my hard disk to an USB disk formatted with |
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> NTFS, issuing the copy command from KDE's dolphin. The freezes became so |
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> long it was impossible to work and then X11 locked up and had to be killed. |
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> |
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> I tried using a preemptive kernel but that didn't seem to help. blkio |
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> and cpu cgroups didn't help either. Ionice seems to be the only solution |
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> but while I'm okay with that, my dad won't be. Can anyone tell me what |
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> is causing this behavior? |
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> |
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> Throughput is good, by the way. That's why I don't suspect a driver issue. |
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> |
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> Thanks in advance! |
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> Florian Philipp |
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> |
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congratulation. You hit 'the bug'. Been around for ages, but for magical |
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reasons kernel dev are unable to see or unable to do something about it. |
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If you are using a vanilla kernel, posting on lkml might be the right |
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thing to do. |
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