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Date: Sat, 25 Aug 2012 08:35:00 -0400
From: Rich Felker <>
Subject: Re: ldso : dladdr support

On Sat, Aug 25, 2012 at 09:42:38AM +0200, boris brezillon wrote:
> >> Do you want me to do some specific tests ?
> >
> > Actually, the main thing I'm interested in is whether the bloom filter
> > is ever beneficial. I took it out trying to streamline the code and
> > shaved about 8% off the lookup time for symbols in the main program,
> > but I didn't investigate how the change affects symbols not found in
> > the first file searched. Would you be interested in running some tests
> > to determine if it might be useful to try adding it back?
> I'll do some tests with multiple levels of big libraries : prog ->
> libtest -> libc -> libb -> liba ...
> How do you get your perf results (specific tools, time measurement
> inside libc code, time measurement in main program, ...)?

I forgot to attach my test code. It's x86-specific (uses rdtsc because
that's the most accurate way) but hopefully that's not a problem.

Note: if searching for symbols in the main program like it's doing as
I have it configured now, you'll need to compile with -rdynamic.


View attachment "gnuhash.c" of type "text/plain" (357 bytes)

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