On 2025-01-07 10:29, Tvrtko Ursulin wrote: > > On 06/01/2025 17:16, Michel Dänzer wrote: >> On 2025-01-02 20:44, Tvrtko Ursulin wrote: >>> >>> "vkgears -present-mailbox" average framerate: >>> >>> Before: 21410.1089 >>> After: 21609.7225 >>> >>> With a disclaimer that measuring with vkgears feels a bit variable, >>> nevertheless it did not look like noise. >> >> That's ~1% difference. IME the frame rate can easily vary more than that during a single run. >> >> The frame rate surely varies by more than 1 fps during each run, so comparing such large average values down to 4 digits after the decimal point doesn't seem very useful. >> >> Doing multiple (at least 3 or more each) before & after runs and comparing the distribution of individual measured values using something like ministat might confirm it's essentially noise, or give more confidence it's not. > > I did multiple runs and I thought from the code changes it would be obvious there is some code there which should go. FWIW, I didn't question that, in fact I don't have any particular opinion on the actual code changes. Claims of performance differences based on two numbers are just a pet peeve of mine. :) > But fair enough, I agree ministat is common practice so I re-did it. Five ~100 second runs each kernel. Absolute numbers are a bit different before I turned on some kernel hardening options since. > > x before > + after > +------------------------------------------------------------+ > | x + | > | x x + | > | x xx ++++ | > | x x xx x ++++ | > | x xx x xx x+ ++++ | > | xxxxx xxxxxx+ ++++ + + | > | xxxxxxx xxxxxx+x ++++ +++ | > | x xxxxxxxxxxx*xx+* x++++++++ ++ | > | x x xxxxxxxxxxxx**x*+*+*++++++++ ++++ + | > | xx x xxxxxxxxxx*x****+***+**+++++ ++++++ | > |x xxx x xxxxx*x****x***********+*++**+++++++ + + +| > | |_______A______| | > | |______A_______| | > +------------------------------------------------------------+ > N Min Max Median Avg Stddev > x 135 21697.58 22809.467 22321.396 22307.707 198.75011 > + 118 22200.746 23277.09 22661.4 22671.442 192.10609 > Difference at 95.0% confidence > 363.735 +/- 48.3345 > 1.63054% +/- 0.216672% > (Student's t, pooled s = 195.681) > > It's a small difference but every little helps. This gives a lot of confidence in the performance gain, thanks! Would be great if you could incorporate at least a summary of this into a commit log somehow. -- Earthling Michel Dänzer \ GNOME / Xwayland / Mesa developer https://redhat.com \ Libre software enthusiast
