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On Thu, Jan 27, 2011 at 03:12:49PM +0100, J. Roeleveld wrote: |
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> On Thursday 27 January 2011 15:05:25 YoYo Siska wrote: |
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> > On Thu, Jan 27, 2011 at 03:33:21PM +0200, Nikos Chantziaras wrote: |
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> > > On 01/27/2011 03:11 PM, Dale wrote: |
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> > > >[...] |
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> > > >I am using the -j option for the first time now. I'm updating KDE. It |
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> > > >seems to work fine. It doesn't scroll all the stuff like with a regular |
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> > > >emerges but this new rig is so fast, I can't read it anyway. I did have |
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> > > >a package to fail and it spit out the error for me to read. |
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> > > |
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> > > You don't need that if you have MAKEOPTS set in your make.conf, |
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> > > which is preferred. The -j option of emerge emerges multiple |
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> > > packages, while with MAKEOPTS set to "-j4" or whatever does a |
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> > > parallel build in the same package (meaning compiling multiple |
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> > > source files at the same time). |
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> > > |
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> > > It's preferred because with "emerge -jN" the last package will only |
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> > > use one CPU, while with "-jN" in MAKEOPTS even the last package will |
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> > > use N CPUs. Furthermore, emerge can't always build N packages at |
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> > > the same time because one can depend on the other, so it will have |
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> > > to wait until the dependency is built. |
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> > |
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> > On the other hand, unpacking, configure and install stages are not |
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> > parallel and emerge can do those in parallel for different packages... |
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> > The best would be somewhere in the middle ;) |
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> > |
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> > |
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> > There are also the load-average options to -j, i.e.: |
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> > MAKEOPTS="-j -l5" emerge -j --load-average=5 .... |
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> > |
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> > which makes make spawn parallel processes while load average is below 5 |
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> > and the same for emerge spawning parallel ebuilds (when make isn't |
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> > parallel enough) |
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> > |
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> > yoyo |
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> |
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> Hmmm... didn't know about that one yet. |
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> Does that mean that by doing it like that, the emerge-process (and compile- |
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> processes) will try to keep the load average at 5 and if that is lower, it |
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> will keep adding more processes? |
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> |
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Yes. |
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It might not be perfect, but mostly it works pretty well. |
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Once make started 10 or so process, which ate all my ram, because I |
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forgot to reenable swap, when I was playing with something before that |
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:) |
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yoyo |
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