runshell LD_HWCAP_MASK=0 optimisation

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Joey Hess 2020-08-03 14:34:15 -04:00
parent e62817c00d
commit 88e5ebcda7
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6 changed files with 68 additions and 13 deletions

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@ -61,3 +61,5 @@ git annex build: 8.20200617+git192-g5849bd634-1~ndall+1
[[!meta author=yoh]]
[[!tag projects/datalad]]
> [[done]] --[[Joey]]

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@ -0,0 +1,23 @@
[[!comment format=mdwn
username="joey"
subject="""comment 19"""
date="2020-08-03T18:16:50Z"
content="""
Implemented the `LD_HWCAP_MASK=0` optimisation, which left only these:
strace -f ./git-annex version 2>&1 | grep ENOENT | grep openat
openat(AT_FDCWD, "/home/joey/src/git-annex/tmp/git-annex.linux//lib/x86_64-linux-gnu/tls/x86_64/libm.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/home/joey/src/git-annex/tmp/git-annex.linux//lib/x86_64-linux-gnu/tls/libm.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/home/joey/src/git-annex/tmp/git-annex.linux//lib/x86_64-linux-gnu/x86_64/libm.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
[pid 697752] openat(AT_FDCWD, "/home/joey/src/git-annex/tmp/git-annex.linux//lib/x86_64-linux-gnu/tls/x86_64/libpcre2-8.so.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
[pid 697752] openat(AT_FDCWD, "/home/joey/src/git-annex/tmp/git-annex.linux//lib/x86_64-linux-gnu/tls/libpcre2-8.so.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
[pid 697752] openat(AT_FDCWD, "/home/joey/src/git-annex/tmp/git-annex.linux//lib/x86_64-linux-gnu/x86_64/libpcre2-8.so.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
There are more failed opens now for locale files for commands like
grep when running it than there are for libraries. So, no need to
consider further prelinking.
I think that rewriting runshell in C would be the
logical next choice, but dunno if it would speed it up by enough to be
worth the effort. So I'm going to close this now.
"""]]