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On 08/14/2017 12:49 PM, M. J. Everitt wrote: |
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> On 14/08/17 08:39, Zac Medico wrote: |
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>> From: Hidehiko Abe <hidehiko@××××××××.org> |
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>> |
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>> doins is written in bash. However, specifically in case that |
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>> too many files are installed, it is very slow. |
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>> This CL rewrites the script in python for performance. |
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>> |
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>> BUG=chromium:712659 |
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>> TEST=time (./setup_board --forace && \ |
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>> ./build_package --withdev && \ |
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>> ./build_image --noenable_rootfs_verification test) |
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>> ===Before=== |
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>> real 21m35.445s |
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>> user 93m40.588s |
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>> sys 21m31.224s |
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>> |
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>> ===After=== |
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>> real 17m30.106s |
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>> user 94m1.812s |
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>> sys 20m13.468s |
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>> |
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> I know I'm gonna get chewed out on this one, but here goes anyway ... |
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> |
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> Surely for a package like chromium, who's build time is already in the |
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> 'hours' range anyway, surely a couple of minutes gain for the install |
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> phase is neither here nor there?! If there were some genuine filesystem |
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> iop gains/etc for this change, I think I'd likely support it further .. |
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It's going to reduce time, power consumption, and heat generation for |
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all portage users. Also, we can use portage.util.file_copy to optimize |
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it further with zero-copy, reflink, and sparse file support. |
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> On this basis, what do the performance differences look like on an |
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> 'average' package |
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Well, it's very inefficient to fork/exec the install command for many |
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files as the existing bash implementation does. The performance |
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difference is related to the number of files. |
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> .. and are there any regressions in this regard?! |
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It's supposed to fallback to calling the install command if there are |
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any unrecognized options, so the intention is for 100% compatibility. |
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> I take issue with the copyright assignment, as I believe the legal .. |
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> err .. IANAL devs are campaigning for full rights to be owned and |
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> enforced by Gentoo Inc LLC in the US .. even if they have no idea what |
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> that means or does .. :] |
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Since it's a BSD-style license, we can copy the code into our project as |
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long as we retain the copyright notice. |
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-- |
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Thanks, |
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Zac |
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