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On Fri, Mar 26, 2010 at 3:47 PM, Daniel Quinn |
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<expendable.0@×××××××××××.org> wrote: |
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> I don't know if this is a hardware issue or not, but I thought that maybe I'd |
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> configured my kernel incorrectly and that this might be a known issue someone |
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> here has run across in the past so here goes: |
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> |
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> My computer is a pretty impressive AMD 64 X2 Dual Core Processor 6400+ box |
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> with 2GB of RAM and for the most part, I just use it to write code at work. |
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> However, whenever I'm doing something CPU-intensive, two things happen: |
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> |
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> * The load on the box goes up to 4 |
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> * The box intermittently wobbles from running at full-speed and dropping to |
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> a crawl. This is best seen while watching Flash videos online, |
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> compressing/encoding video, or compiling. Everything is fine for a few |
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> minutes, then suddenly the rate of compiling/compression/playback etc. |
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> drops to a crawl for about 1-3minutes, then back up to full speed. |
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> |
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> I don't know why it's happening. I've tried various kernel options with no |
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> change in behaviour. Outside of that though, I don't know what to try. |
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> Suggestions welcome :-( |
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|
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My initial thoughts, it sounds like what I experienced a few kernels |
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ago when they introduced the new group scheduler features. In my case |
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I disabled "Group CPU scheduler" in kernel config and changed from |
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SLUB back to SLAB. Also perhaps try to change your preemption model, |
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timer frequency, NO_HZ mode. These things have all had noticeable |
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differences to me in responsiveness over the years. |
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|
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If it's not a kernel issue, perhaps use "nice" to tame CPU-hungry |
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processes, or "ionice" if they are disk-intensive. |
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|
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Be sure your Video Card is not overheating or going into low-power |
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mode. Nvidia cards go into a super-slow-mode when they overheat |
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(happened to me 3 times when the fan on the card died). When that |
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happened, for example my FPS in glxgears would go from thousands down |
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to double digits... I could see lines painting on the screen, it was |
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painfully slow. |
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|
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Also, if your CPU has frequency scaling make sure it's not gone crazy, |
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cat /proc/cpuinfo to see CPU speed, or powertop might be a more |
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friendly way to view the P-States. |
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|
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Download memtest86+ from memtest.org and run it to be sure you don't |
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have any faulty RAM (in my experience tests 5 and 8 are the only ones |
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that ever show any errors, so you can save time by only running one |
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full pass of all tests and then a multiple passes of 5 and 8 just to |
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be sure it's good) |
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