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On Sat, Dec 26, 2009 at 4:54 PM, Paul Hartman |
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<paul.hartman+gentoo@×××××.com> wrote: |
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> Hi, |
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> |
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> I got a Nokia N900 linux internet tablet/phone a few days ago, and |
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> when I connect it in USB Mass Storage mode to a Windows Vista computer |
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> I can write at 17MB/sec, but when I connect it to my Gentoo box my |
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> writes are really slow, between 500-900kb/sec depending on if I mount |
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> in "sync" mode or not. As far as I know it should be just a totally |
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> standard/generic mass storage device. (there were no drivers or |
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> software install needed in windows, it just worked) |
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> |
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> Other USB devices plugged into the same port go full speed, and AFAIK |
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> everything appears as if it should be high speed USB 2.0. Has anyone |
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> seen something like this before? I'm not sure what the deal is. It |
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> takes 20 minutes to copy 1 gigabyte from Linux and takes just under 1 |
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> minute to do the same in Windows. |
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> |
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> I'm not sure about debugging USB or what the options are. Everything |
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> I've used previously has worked without any hassle. |
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|
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Solved. The problem was CFQ I/O scheduler. It was several times slower |
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than the others, for whatever reason. |
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|
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Here is the scoreboard: |
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|
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single-file: 1m25s |
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|
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multi-file (same total size): |
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cfq: 6m51.439s |
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noop: 3m0.733s |
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anticipatory: 1m44.348s |
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deadline: 1m36.804s |
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|
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So, the winner is deadline. CFQ doesn't make it to the podium. :) |
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|
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Thanks, |
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Paul |
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