Just another note: I suspect that the `reshape()` might be the guilty party. I am just guessing here, but I suspect that the reshape() forces a memory copy, while a regular slice just creates kind of symlink to the original data. Furthermore, I suspect that the memory copy would mean that when you try to read from the newly created variable, you have to fetch it from RAM, despite the fact that the CPU cache already has a perfectly good copy of the same data.
Cheers, Daniel. On 20 September 2015 at 21:25, Daniel Carrera <dcarr...@gmail.com> wrote: > Whoo hoo! It looks like I got another ~6x or ~7x improvement. Using > Profile.print() I found that the hottest parts of the code appeared to be > the if-conditions, such as: > > if o < b_hist[j,3] > > It occurred to me that this could be due to cache misses, so I rewrote the > code to store the data more compactly: > > - b_hist = reshape(sim.b[d, 1:t, i, :], t, 3) > + b_hist_1 = sim.b[d, 1:t, i, 1] > + b_hist_3 = sim.b[d, 1:t, i, 3] > ... > - if o < b_hist[j,3] > + if o < b_hist_3[j] > > > So, instead of an 3xN array, I store two 1xN arrays with the data I > actually want. I suspect that the biggest improvement is not that there is > 1/3 less data, but that the data just gets managed differently. The upshot > is that now the program runs 208 times faster for me than it did initially. > For me time execution time went from 45s to 0.2s. > > As always, the code is updated on Github: > > https://github.com/dcarrera/sim > > Cheers, > Daniel. > > > > On 20 September 2015 at 20:51, Seth <catch...@bromberger.com> wrote: > >> As an interim step, you can also get text profiling information using >> Profile.print() if the graphics aren't working. >> >> On Sunday, September 20, 2015 at 11:35:35 AM UTC-7, Daniel Carrera wrote: >>> >>> Hmm... ProfileView gives me an error: >>> >>> ERROR: panzoom not defined >>> in view at /home/daniel/.julia/v0.3/ProfileView/src/ProfileViewGtk.jl:32 >>> in view at /home/daniel/.julia/v0.3/ProfileView/src/ProfileView.jl:51 >>> in include at ./boot.jl:245 >>> in include_from_node1 at ./loading.jl:128 >>> while loading /home/daniel/Projects/optimization/run_sim.jl, in >>> expression starting on line 55 >>> >>> Do I need to update something? >>> >>> Cheers, >>> Daniel. >>> >>> On 20 September 2015 at 20:28, Kristoffer Carlsson <kcarl...@gmail.com> >>> wrote: >>> >>>> https://github.com/timholy/ProfileView.jl is invaluable for >>>> performance tweaking. >>>> >>>> Are you on 0.4? >>>> >>>> On Sunday, September 20, 2015 at 8:26:08 PM UTC+2, Milan Bouchet-Valat >>>> wrote: >>>>> >>>>> Le dimanche 20 septembre 2015 à 20:22 +0200, Daniel Carrera a écrit : >>>>> > >>>>> > >>>>> > On 20 September 2015 at 19:43, Kristoffer Carlsson < >>>>> > kcarl...@gmail.com> wrote: >>>>> > > Did you run the code twice to not time the JIT compiler? >>>>> > > >>>>> > > For me, my version runs in 0.24 and Daniels in 0.34. >>>>> > > >>>>> > > Anyway, adding this to Daniels version: >>>>> > > https://gist.github.com/KristofferC/c19c0ccd867fe44700bd makes it >>>>> > > run in 0.13 seconds for me. >>>>> > > >>>>> > > >>>>> > >>>>> > Interesting. For me that change only makes a 10-20% improvement. On >>>>> > my laptop the program takes about 1.5s which is similar to Adam's. >>>>> So >>>>> > I guess we are running on similar hardware and you are probably >>>>> using >>>>> > a faster desktop. In any case, I added the change and updated the >>>>> > repository: >>>>> > >>>>> > https://github.com/dcarrera/sim >>>>> > >>>>> > Is there a good way to profile Julia code? So I have been profiling >>>>> > by inserting tic() and toc() lines everywhere. On my computer >>>>> > @profile seems to do the same thing as @time, so it's kind of >>>>> useless >>>>> > if I want to find the hot spots in a program. >>>>> Sure : >>>>> http://julia.readthedocs.org/en/latest/manual/profile/ >>>>> >>>>> >>>>> Regards >>>>> >>>> >>> >
