Messages in this thread | | | Date | Fri, 25 Jan 2002 23:38:51 -0500 | Subject | Re: [ACPI] ACPI mentioned on lwn.net/kernel | From | Andrew Pimlott <> |
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On Fri, Jan 25, 2002 at 11:33:44PM -0500, Alexander Viro wrote: > > On Sat, 26 Jan 2002, Jamie Lokier wrote: > > > I once wrote a Perl script that needed to know the current directory. > > It did: > > > > use POSIX 'getcwd' > > getcwd(...) > > > > After a few months, I was annoyed by the slowness of this script > > (compared with other scripts) and decided to try speeding it up. It > > turns out that the above two lines took about 0.25 of a second, and that > > was the dominant running time of the script. > > > > I replaced getcwd() with `/bin/pwd`. Lo! It took about 0.0075 second. > > > > Says very good things about Linux' fork, exec and mmap times, and about > > Glibc's dynamic loading time, I think. > > Most likely it says very bad things about getcwd() implementation in Perl > compared to sys_getcwd() in the kernel.
No no no--it says very bad things about 'use POSIX', and in general about overhead-creep in the perl library.
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