increase performance of background parser

[Andreas Pakulat]

On 01.11.11 20:52:54, Gerhard Stengel wrote:
> Hi,
> 
> I'm working with a quite big project which the kdevelop background parser 
> needs almost an hour to scan each time I open it. The CPU load stays quite low 
> (< 30%) as you would expect for a job running in the background, but I'd wish 
> to cut down the time a bit. My computer's CPU has 8 cores, so even if the 
> parser consumed more resources, there'd be enough left. I've already increased 
> to 8 threads.
> Would it be possible to add some feature in the settings dialogue to increase 
> the resources the parsing may take?

As Sven already said increasing the number of threads won't help, it may
even hurt due to lock-contention (i.e. some of the threads need to wait
more/longer before they can continue).

The only things that can help speeding up kdevelop's parsing performance
significantly at the moment are: SSD to remove all IO-bottlenecks and
having a CPU thats running with >3GHz so the code can be executed
faster.

That being said, if you want to help find possible new bottlenecks in
the codebase (there are some known ones which are unfortunately hard to
fix) then run kdevelop in valgrinds callgrind and/or helgrind and upload
the resulting data somewhere for the devs to look at. Make sure to build
kdevelop in RelWithDebInfo mode so optimizations are applied but
debug-info is somewhat retained.

Andreas