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Re: parallelizing more actions
From: |
Ludovic Courtès |
Subject: |
Re: parallelizing more actions |
Date: |
Sat, 11 Nov 2017 12:25:01 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) |
Hi Efraim,
Efraim Flashner <address@hidden> skribis:
> While rebuilding glibc-final on aarch64 I realized that the 'strip phase
> took 235 seconds. The relevant code for 'strip from gnu-build-system is
> in guix/build/gnu-build-system.scm, starting at line 340, with the
> actual stripping starting at 398. When I changed 'for-each' to
> 'par-for-each' the time dropped from 235 seconds to 215, about an 8.5%
> savings. I'm pretty sure most of that time was spent failing to strip
> certain files, but it is still a savings.
Is it on a spinning hard disk or an SSD? My guess is that most of the
time is I/O, and that parallelizing doesn’t buy us much (indeed, 8.5% is
not that much, far from a linear speedup.)
So I’m mildly reluctant to parallelizing this particular piece of code.
Thanks,
Ludo’.