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On Saturday 17 February 2007, Alex Schuster wrote: |
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> > Shouldn't top have provided some kind of info for why the CPU usage |
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> > was 100% for 5 minutes straight? If it does display trends, |
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> > shouldn't it have picked up on that one? |
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> |
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> I bet it was updatedb. This is what top shows me when it is running: |
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|
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or eupdatedb, or prelink... :-) |
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|
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> Cpu(s): 15.6% us, 12.6% sy, 0.3% ni, 0.0% id, 70.2% wa, 1.3% hi, |
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> 0.0% si PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ |
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> COMMAND 1563 root 18 0 1936 928 528 R 8.9 0.2 0:09.68 |
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> updatedb |
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> |
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> Whatever this "wa" entry is, probably something with I/O related |
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> waiting, it seems is it not being taken into account for the %CPU |
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> culumn entry of the process. |
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|
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"wa" is "wait" - a process is trying to do IO and it is being blocked as |
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something else is using a resource the process wants to use. SO it sits |
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and does nothing, much the same way you sometimes sit in your car and |
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do nothing at the McDonalds drive-through queue. |
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|
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Usually a blocked process will consume no cpu time (as it's doing |
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nothing), but it can slow the machine down and make it less responsive |
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while many processes sit and wait |
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|
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alan |
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|
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-- |
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Optimists say the glass is half full, |
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Pessimists say the glass is half empty, |
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Developers say wtf is the glass twice as big as it needs to be? |
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|
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Alan McKinnon |
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alan at linuxholdings dot co dot za |
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+27 82, double three seven, one nine three five |
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-- |
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gentoo-user@g.o mailing list |
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