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On Thu, 22 Sep 2005 14:59:55 -0700 |
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Mark Knecht <markknecht@×××××.com> wrote: |
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> Hi, |
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> I'm looking at this mythbackend server machine using top. Sometimes |
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> the CPU usage goes to essentially 100%, but only in the 'wa' section. |
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> What is 'wa'? I searched through the man page but didn't see anything |
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> about this. |
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> |
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It's described in the vmstat man page. You're supposed to be clairvoyant about |
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these things and know that virtual memory stats is where cpu time is described. :) |
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It's "Time spent waiting for IO." The cpu can't do anything until IO is |
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completed - typically this is some kind of DMA transfer. |
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> I'm suspecting that this machine has stopped being able to keep up |
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> with MythTV due to something using up CPU time. I found that one of my |
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> wife's screensavers (Fireworks) was using 70-90% CPU so I've turned |
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> that off and things seem much better. Now when watching top I never |
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> see anything using more than a few %, but this 'wa' thing persists. |
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> |
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Nope, it's just slow doing IO - bottleneck in either disk to memory, video to memory, |
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or memory to network. |
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> |
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> top - 14:51:47 up 4:19, 3 users, load average: 1.75, 1.88, 1.58 |
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> Tasks: 91 total, 2 running, 88 sleeping, 0 stopped, 1 zombie |
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> Cpu(s): 0.3% us, 0.3% sy, 0.0% ni, 0.0% id, 97.7% wa, 0.0% hi, 1.7% si |
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> Mem: 499052k total, 493560k used, 5492k free, 3140k buffers |
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> Swap: 1052216k total, 368k used, 1051848k free, 342352k cached |
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> |
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Looks like it might help a bit to increase the systems main memory to 1 GB. It'll eliminate |
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the swapping and will increase the available in-memory filesystem buffering. |
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Bob |
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- |
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-- |
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