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On 2020-06-21 11:53, Dr Rainer Woitok wrote: |
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> Greetings, |
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> |
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> is there any difference between running "emerge --jobs=1 ..." and runn- |
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> ing "MAKEOPTS=-j1 emerge ..."? |
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--jobs=1 starts one package build at a time, possibly using many parallel |
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processes - depending on MAKEOPTS and how the build works. |
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MAKEOPTS sets the number of parallel processes within one package build. |
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They are complementary, and you can combine them. However frequently |
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a series of packages have dependencies (a before b before c), so starting |
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multiple --jobs may not have any effect. Or it may, e.g. in the case of |
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rebuilds or independent packages that often only use one process to build, |
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e.g. perl modules or something smaller. --jobs can really make a difference |
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since otherwise you would suffer from portage/script/shell overhead relative |
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to the actual work being performed. |
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make offers the -l parameter that constrains the number of processes by |
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load, and adjusts them accordingly. As an example, with 8 cores you could |
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use MAKEOPTS="-j8 -l8" to enable inter-ebuild parallelism and a max. load |
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for one package, then start several --jobs to build independent packages |
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without waiting for each other. |
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Hope this helps. |
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-h |
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