From: Thomas Petazzoni via buildroot <buildroot@buildroot.org>
To: David Laight <David.Laight@ACULAB.COM>
Cc: "yann.morin@orange.com" <yann.morin@orange.com>,
"buildroot@buildroot.org" <buildroot@buildroot.org>
Subject: Re: [Buildroot] [PATCH] support/scripts/check-host-libs: add new check on host binaries/libs
Date: Wed, 21 Sep 2022 11:05:00 +0200 [thread overview]
Message-ID: <20220921110500.5128d0b9@windsurf> (raw)
In-Reply-To: <9ce68f90a18642ad96e8010fd87dd15f@AcuMS.aculab.com>
Hello,
On Wed, 21 Sep 2022 08:23:54 +0000
David Laight <David.Laight@ACULAB.COM> wrote:
> Think a bit further and you can remove the exec of cmp, eg:
>
> $ time find /usr/lib -type f | (ELF="$(printf '\x7f\x45\x4c\x46')"; while read f; do read l <"$f" && [ "${l#$ELF}" != "$l" ] && echo $f; done )| wc -l
Thanks for the input and proposal. Isn't read l <"$f" going to read
each file entirely in memory?
> That takes a few seconds on my system.
On my system, your command took 19 seconds. When doing this kind of
test, make sure to drop the contents of the page cache first by doing:
echo 3 > /proc/sys/vm/drop_caches
Before each experiment. On my machine, with the page cache contents
dropped, it takes 19-20 seconds to run your command the first time.
Subsequent runs only last 12 seconds.
Thomas
--
Thomas Petazzoni, co-owner and CEO, Bootlin
Embedded Linux and Kernel engineering and training
https://bootlin.com
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next prev parent reply other threads:[~2022-09-21 9:05 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-20 6:45 [Buildroot] [PATCH] support/scripts/check-host-libs: add new check on host binaries/libs Thomas Petazzoni
2022-09-20 7:46 ` yann.morin
2022-09-20 8:35 ` Thomas Petazzoni
2022-09-20 9:11 ` yann.morin
2022-09-20 9:19 ` Thomas Petazzoni via buildroot
2022-09-20 9:40 ` yann.morin
2022-09-20 9:54 ` Thomas Petazzoni
2022-09-20 19:48 ` Arnout Vandecappelle
2022-09-21 7:26 ` yann.morin
2022-09-21 8:23 ` David Laight
2022-09-21 8:41 ` yann.morin
2022-09-21 9:05 ` Thomas Petazzoni via buildroot [this message]
2022-09-21 9:09 ` yann.morin
2022-09-21 9:24 ` David Laight
2023-04-16 20:10 ` Yann E. MORIN
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