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Hello, |
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On Wed, Nov 22, 2017 at 12:52 AM, Raffaele Belardi |
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<raffaele.belardi@××.com> wrote: |
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> Hi, |
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> |
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> rebuilding system and world with gcc-7.2.0 on a 6-core AMD CPU I have the impression that |
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> most of the ebuilds limit parallel builds to 1, 2 or 3 threads. I'm aware it is only an |
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> impression, I did not spend the night monitoring the process, but nevertheless every time |
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> I checked the load was very low. |
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> |
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Assuming all of your compilation is on a RAM disk, there are two main |
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bottlenecks that are easy to spot: network access (downloading new |
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packages) and dependency chokepoints (packages must be compiled in a |
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chain). Other potential chokepoints like disk access are negligible in |
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my experience, though for one merge I did have two or three ebuilds |
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fighting for disk IO "lock up" a system. |
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If all dependencies have been satisfied on your system I invite you to |
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merge a bunch of packages at once (@world?), you should notice greater |
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parallelism. |
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> Does anyone have real-world statistics of CPU usage based on gentoo world build? |
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> |
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I've considered ways to gather these statistics off and on over the |
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years, but it is easy to start sinking a lot of time into it. It is |
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possible the data you want exists, but I have not found any extant |
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solution involving portage that provides that detail of logging.* |
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Cheers, |
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R0b0t1 |
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* Someone will prove me wrong in 3... 2... 1... |
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