getaddrinfo performance problems

Alexander Komyagin komyagin at
Mon Apr 16 14:22:43 UTC 2012

Hi, Ed. Which version of uclibc you are using?

I've spent a lot of time in that particular case with getaddrinfo(), and
as of 0.9.32 it behaves correctly. Make sure that this problem is really
related to resolving (try plain old sectioned printf debugging :) ).

Also try the attached patch to see if it helps.

On Mon, 2012-04-16 at 15:05 +0100, Ed W wrote:
> Hi, I'm suffering extreme performance problems with getaddrinfo being 
> used by ipset to do conversions from IP textual strings to number.  
> Although the IP address is textual there is a reverse DNS lookup 
> performed and in the event that my resolver is slow, this is sometimes 
> taking 60seconds or so to return
> (specifics are the box has multiple internet connections, if one 
> connection is dead we need ipset to force use of another connection, but 
> ipset does a reverse lookup down the dead connection which seems to take 
> lots of multi-sec timeout)
> Is anyone sitting on a patch to optimise getaddrinfo for the situation 
> of hint = AI_NUMERICHOST ?  Otherwise I will investigate, but would 
> appreciate a helping hand from someone more familiar with the code?  
> Willing to pay for a fix?
> Many thanks
> Ed W
> _______________________________________________
> uClibc mailing list
> uClibc at

Best wishes,
Alexander Komyagin
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