Speed of Krita 2.4

[Boudewijn Rempt]

On Saturday 30 July 2011 Jul, Silvio Heinrich wrote:
> Am 29.07.2011 23:30, schrieb JL VT:
> > I don't know how fast Krita is in the other branches (I haven't tested)
> > however I'd like to ask if there's a good date to start feeling really
> > worried about speed?, I don't want 2.4 to be a single bit slower than
> > 2.3, so I'd like to start hacking to try to find where our current
> > bottlenecks are; but I don't know which parts deep in Krita to touch
> > without stepping on other developer's toes, moreover, my fears may be
> > unfounded, maybe we're just a couple weeks shy of a branch merge solving
> > all these problems, but, again, I haven't kept up enough with our IRC
> > backlogs and Krita branches to be sure.
> > 
> > Should I be worried?.
> > 
> > Is there an upcoming branch I should be testing to help with the speed
> > bottlenecks instead?.
> > 
> 
> As far as I know we have two big bottle necks.
> The first is the creation and transformation (rotation, scaling) of the
> brush masks. The last time I profiled krita it spent 20-30% (I can't
> remember exactly anymore) of the whole processing time while painting
> with this operations.

Geoffry and Sven have done quite a bit of work here -- we might gain more by using vectorization, but nobody has quite managed that. It's also good to remember that the callgrind results are percentages -- which means that 30% doesn't necessarily mean it's bad, just that mask creation takes about as much time as projection updating.

> 
> The second one is the huge memory consumption of krita. I think it would
> be unlikely that the process of painting itself gets faster with a lower
> memory consumption but the overall execution of krita.
> If a lot of memory is used (and I'm talking about gigabytes) the OS
> needs a lot more processing time to manage the memory what makes krita
> slower too. And its not uncommon that you reach the memory limit of your
> system when using krita. I often have 2-4GBs in use.
> 
> So if you want to address one of this two issues... :D even solving just
> one would be a huge improvement.

I agree that memory usage is a big concern at the moment. We're using gobs of memory to make Krita faster, but I still would like to see the results of keeping all the tiles compressed in memory. If I look at the memory profile of Photoshop 7, I'm almost convinced that that's what they do: the memory consumption is too small for the big image I loaded into it.

-- 
Boudewijn Rempt
http://www.valdyas.org, http://www.krita.org, http://www.boudewijnrempt.nl