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Date: Sun, 26 Aug 2012 00:37:17 +0200
From: musl <>
Subject: Re: ldso : dladdr support

On 26/08/2012 00:13, musl wrote:
> On 24/08/2012 20:38, Rich Felker wrote:
>> On Fri, Aug 24, 2012 at 09:29:29AM +0200, musl wrote:
>>> I tested it and it works well.
>> Is there anything I changed that you think might be better done a
>> different way?
>>> My tests are based on small libs (with a small set of shared symbols).
>>> I mixed libs with gnu hash and sysv hash.
>>> Tried to resolve symbols via dlsym.
>>> Have you tested it on big libraries ?
>> No, just very minimal testing.
>>> 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?
>> Since it seems to be working/non-broken right now, I'll probably go
>> ahead and commit soon unless you find a major problem I've overlooked.
>> Then we can work on improving it once it's in the repo.
> I executed your test program (gnuhash) with and without bloom filter test, and I get pretty much the same results in
> both cases if the symbol is defined.
> What compiler option did you use to compile gnuhash.c ?
> I also tried to search for a missing symbol and the version with bloom filter is 3% faster.
> I'll do more tests with bigger libs and different linker optimizations (some linker optims change the number of buckets
> in the hash table => less entries per hash chains => faster search in case there's no valid entry for a given name).
Here is the patch I used to add bloom filter test.
>> Rich

View attachment "gnuhash-bloom-filter.diff" of type "text/x-patch" (959 bytes)

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