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Hilco Wijbenga posted on Sat, 12 Nov 2011 16:05:36 -0800 as excerpted: |
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> By the way, is there a noticeable difference in build time (for |
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> relatively large builds) when logging to the console is off? Not |
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> important, just curious. |
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There can be. AFAIK it's not too bad when output is to a vgacon text- |
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console, but to frame-buffer (kms mode text console or X) tends to be |
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more CPU intensive and to slow things down if you're bottlenecking on CPU |
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as is often (but not always, especially on multi-core systems without |
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emerge --jobs set to allow multiple parallel package emerges at once, as |
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well as MAKEOPTS=-j, to allow multiple make jobs with a single merge job) |
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the case. Terminal windows tend to use what a text console framebuffer |
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does, often more, depending on effects and how much is hardware |
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accelerated. |
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Perhaps the biggest efficiency gain, however, if you have 4 gig plus of |
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memory (and a 64-bit system to handle it reasonably efficiently), is to |
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point PORTAGE_TMPDIR at a tmpfs and control its size and the number of |
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parallel jobs to avoid more than a few MB of swappage. Based on my |
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experience here, with four or even at two cores, the load average doesn't |
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bog down the system anywhere close to what disk I/O does, regardless of |
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whether it's swap or conventional disk I/O access. Putting the temp-dir |
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in tmpfs means a lot of scratch files are never written to disk at all, |
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thus saving that disk access, and theoretically it could even save if |
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you're into swap (forums or user list for the details), but obviously far |
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less then, so I now set jobs and load average to best control, if |
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indirectly, for memory usage including the tmpfs, as opposed to direct |
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CPU load control. |
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But there's whole threads on optimizing emerges on the forums and user |
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list. This really isn't the place for further discussion on that. |
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-- |
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Duncan - List replies preferred. No HTML msgs. |
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"Every nonfree program has a lord, a master -- |
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and if you use the program, he is your master." Richard Stallman |