strange performance differences of 1.2.2 vs 1.2.5

Sean Chittenden sean at
Sun Jun 1 23:30:40 UTC 2008

> That's a good guess (Brian? You know about that?:) ... but a bit  
> doubtful.
> That gettimeofday(2) call that was changed is only made once per  
> second
> asyncronously. In order to have such a large performance impact we'd  
> be
> looking at some more broad changes.

Hrm....  yeah, it's wrapped in an evtimer_set(3) call.  Wait...

libevent(3's gettime() static function will use gettimeofday(2) if  
either HAVE_CLOCK_GETTIME and CLOCK_MONOTONIC aren't defined and  
use_monotonic is false.  Chris, I haven't profiled anything but it may  
be worth looking into upgrading libevent(3) since it seems as though  
the gettimeofday(2)/gettime() foo was still being toyed with around  
the timeframe of libevent 1.3.  YMMV as this was only a passing glance  
at the problem w/ the details provided.  :~)  gprof(1) memcached(8) if  
you want more specific guidance as to what it could be.  -sc



Sean Chittenden
sean at

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