Hello James, I was going through the discussion over the bug #2080 handled currently by Anurag. I too was thinking of replacing the animation algo, which currently is sine function. I was having some questions in mind after looking at your research. "When launcher is disabled, the time saving is more, as compared to SVG complexity." If we are not for removing animation, then why not use a simple integer based algorithm instead of a floating based sine algorithm. In terms of graphics, integer based algorithms (Bresenham, Mid-point, etc) work faster than floating point based. If we can use a 'Busy-Cursor' then its fine. But if we still want to continue with the animation, why not change the algorithm for the animation that is done? Regards, Dipankar <div class="gmail_quote"> On Thu, Oct 28, 2010 at 9:04 AM, James Cameron <<a href="mailto:quozl@laptop.org">quozl@laptop.org</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> Earlier in the context of SL#2080 patch review, I had said "the launcher is stealing CPU cycles from the startup of the activity, the task run queue shows this during a launch. I wonder if activities might start up faster if there was no launcher, just a busy cursor." Looks like activities would start faster; between one and four seconds, mostly depending on the activity, and slightly depending on the icon complexity. Details below. -- Research: will activities start faster if there is no launcher? Method: using an XO-1, freshly installed with Sugar 0.84.22, as part of OLPC OS 10.1.2 build os852, test the startup time of three activities (Memorize, Moon and Chat), remove the launcher, retest, subtract. The launcher is implemented by source file launcher.py in /usr/lib/python2.6/site-packages/jarabe/view/ ... the modification made is attached as a patch. The times were captured with a stopwatch. The timing began when "Start" was selected from the list view, and ended once the activity had completed display of the UI. Result: a. unmodified launcher.py Memorize-34 9.43s, 9.56s, 9.51s Moon-11 11.58s, 11.60s, 11.65s Chat-65 6.65s, 6.54s, 6.59s b. modified launcher.py (black background, no animation), Memorize-34 7.60s, 7.63s, 7.60s Moon-11 7.78s, 7.78s, 7.95s Chat-65 5.04s, 4.93s, 4.88s c. calculated cost of launcher Memorize-34 1.89s Moon-11 3.73s Chat-65 1.64s Diagnosis: removing the launcher animation saved between one and four seconds of startup time. The saving was greatest for the Moon activity. -- Research: determine if the SVG icon for the Moon activity contributes to the delay. Method: swap the icons, restart Sugar, retest only Chat activity with Moon icon. Result: a. unmodified launcher.py Chat-65 7.83s, 7.59s, 7.62s b. modified launcher.py (black background, no animation), Chat-65 4.99s, 4.87s, 4.90s c. calculated cost of launcher Chat-65 2.75s (greater than previous) d. calculated cost of moon icon over chat icon Chat-65 1.09s Diagnosis: the degree of saving has a little to do with the SVG icon complexity. The degree of saving has much to do with the mix of operations performed by the activity during startup. -- So, between 23 and 92 wasted days of looking at the launcher across two million laptops. Good time to think and plan, kids. -- James Cameron <a href="http://quozl.linux.org.au/" target="_blank">http://quozl.linux.org.au/</a> _______________________________________________ Sugar-devel mailing list <a href="mailto:Sugar-devel@lists.sugarlabs.org">Sugar-devel@lists.sugarlabs.org</a> <a href="http://lists.sugarlabs.org/listinfo/sugar-devel" target="_blank">http://lists.sugarlabs.org/listinfo/sugar-devel</a> </blockquote></div>