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2018-02-08 20:13 GMT+02:00 Rich Freeman <rich0@g.o>: |
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> On 08/02/18 19:11, gevisz wrote: |
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>> |
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>> I never used tmpfs for portage TMPDIR before and now decided to give it a |
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>> try. |
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>> |
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>> I have 8GB of RAM and 12GB of swap on a separate partition. |
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>> |
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>> Do I correctly understood |
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>> https://wiki.gentoo.org/wiki/Portage_TMPDIR_on_tmpfs |
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>> that I can safely set in the fstab the size of my tmpfs to 12GB so |
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>> that the chromium could be emerged in tmpfs (using the swap) |
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>> without the need to set notmpfs.conf for chromium and the likes. |
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> |
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> You can try it, but for Chromium these days you might find that still |
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> doesn't perform great. I have 16GB of RAM (no swap) and have moved |
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> back to building on SSD for that one package (with ccache to help). |
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> |
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> In an ideal world swap would STILL be better than building on disk, |
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> because it gives the kernel fewer constraints around what gets written |
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> to disk. |
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|
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> Anything written to disk MUST end up on the disk within the dirty |
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> writeback time limit. Anything written to tmpfs doesn't ever have to |
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> end up on disk, and if it is swapped the kernel need not do it in any |
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> particular timeframe. Also, the swapfile doesn't need the same kinds |
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> of integrity features as a filesystem, which probably lowers the cost |
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> of writes somewhat (if nothing else after a reboot there is no need to |
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> run tmpreaper on it). |
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|
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> So, swapping SHOULD still be better than building on disk, because any |
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> object file that doesn't end up being swapped is a saved disk IO, and |
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> the stuff that does get swapped will hopefully get written at a more |
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> opportune time vs forcing the kernel to stop what is doing after 30s |
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> (by default) to make sure that something gets written no matter what |
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> (if it wasn't deleted before then). |
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|
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Thank you for the reply. |
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I probably try a pure tmpfs + swap solution. If it fails some day, I will |
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then add notmpfs exceptions. |
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|
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However, it probably won't be sooner than |
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# emerge --update --deep --with-bdeps=y --newuse --backtrack=90 --ask |
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world --exclude chromium |
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fails because of the "--exclude chromium" part :), as I have already compiled |
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the recent vertion of chromium with /var/tmp/portage on the hard disk and |
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it took more than 24 hours on my old AMD Athlon X2 with j2 option. :( |
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