On Thu, Sep 25, 2008 at 12:26 AM, Erik Garrison <[EMAIL PROTECTED]> wrote: > On Wed, Sep 24, 2008 at 07:51:30PM +0200, Tomeu Vizoso wrote: >> On Wed, Sep 24, 2008 at 7:25 PM, Eduardo H. Silva <[EMAIL PROTECTED]> wrote: >> > Wow, just tried Erik's instructions for using xcompmgr, and it's >> > amazing how swift the frame slides, and how I don't see any screen >> > redraws. The experience is totally more fluid. Does it degrade overall >> > performance? If not much, and if that performance degradation could be >> > recovered in another area in Sugar (general performanfe improvements), >> > I'd vote for this to exist in joyride and even part of future stable >> > builds. >> >> AFAIK, the only tradeback (and the reason why it hasn't been activated >> yet) is that we must pay composition with increased memory usage. >> Composition basically saves us unnecessary redraws by keeping in >> memory copies of the windows contents. >> >> Martin Dengler did back in March an excellent job quantifying this tradeback: >> >> http://lists.laptop.org/pipermail/sugar/2008-March/004718.html > > Using similar methods (ps_mem.py), I get roughly the same results. > > I run ps_mem.py at five places, before and after enabling composite with > 0 to 4 activites running (Chat, Paint, Write, and Browse). (I get ten > files named {before,after}_*_activity, and then grep them to make > comparitive claims.) > > > We can see that Activities use about the same amount of memory before > and after the change: > > > e.g. Paint: > > before_1_activity: 9.3 MiB + 4.2 MiB = 13.5 MiB Paint <65be2c3b > before_2_activity: 9.2 MiB + 3.1 MiB = 12.3 MiB Paint <65be2c3b > before_3_activity: 9.4 MiB + 2.5 MiB = 11.9 MiB Paint <65be2c3b > before_4_activity: 9.4 MiB + 2.1 MiB = 11.5 MiB Paint <65be2c3b > > after_1_activity: 9.3 MiB + 4.2 MiB = 13.5 MiB Paint <eb84d7a4 > after_2_activity: 9.3 MiB + 3.1 MiB = 12.4 MiB Paint <eb84d7a4 > after_3_activity: 9.2 MiB + 2.5 MiB = 11.7 MiB Paint <eb84d7a4 > after_4_activity: 9.2 MiB + 2.1 MiB = 11.3 MiB Paint <eb84d7a4 > > > e.g. Write: > > before_3_activity: 19.4 MiB + 2.8 MiB = 22.2 MiB Write <d2756bab > before_4_activity: 19.4 MiB + 2.4 MiB = 21.8 MiB Write <d2756bab > > after_3_activity: 19.4 MiB + 2.8 MiB = 22.2 MiB Write <d863e164 > after_4_activity: 19.4 MiB + 2.4 MiB = 21.8 MiB Write <d863e164 > > > However, there is an obvious memory difference between the two > situations: > > [ total memory usage ] > > before_0_activity- 86.4 MiB > before_1_activity- 98.0 MiB > before_2_activity- 126.6 MiB > before_3_activity- 146.2 MiB > before_4_activity- 154.9 MiB > > after_0_activity- 88.5 MiB > after_1_activity- 109.8 MiB > after_2_activity- 138.0 MiB > after_3_activity- 162.7 MiB > after_4_activity- 173.2 MiB > > When composition is enabled, we used 18.3 MiB more to run the same 4 > activities. > > > Following Martin Dengler's lead, we discover that this memory is mostly > used by the X server: > > bash-3.2# grep Xorg before* > before_0_activity: 3.1 MiB + 390.5 KiB = 3.5 MiB Xorg > before_1_activity: 3.2 MiB + 430.0 KiB = 3.6 MiB Xorg > before_2_activity: 3.4 MiB + 420.0 KiB = 3.9 MiB Xorg > before_3_activity: 3.7 MiB + 509.5 KiB = 4.2 MiB Xorg > before_4_activity: 3.7 MiB + 507.5 KiB = 4.2 MiB Xorg > > bash-3.2# grep Xorg after* > after_0_activity: 3.0 MiB + 342.5 KiB = 3.3 MiB Xorg > after_1_activity: 10.9 MiB + 445.0 KiB = 11.4 MiB Xorg > after_2_activity: 13.1 MiB + 425.5 KiB = 13.5 MiB Xorg > after_3_activity: 18.0 MiB + 506.0 KiB = 18.5 MiB Xorg > after_4_activity: 19.9 MiB + 504.0 KiB = 20.4 MiB Xorg > > A little under 15 MiB of increase. > >> >> I'd vote for activating composition ASAP once we have a 9.1 joyride >> branch and see how we can find the sweetest spot between speed and >> memory usage. >> > > I agree. > > There also may be bugs which we need to shake out. If this is a feature > we know we want for 9.1, the sooner we start testing the better. >
FWIW, sometime back, I did some benchmarks with a composite enabled Metacity - results at http://www.mail-archive.com/[email protected]/msg03613.html Jim had suggested some memory saving tricks at http://www.mail-archive.com/[email protected]/msg03647.html Thanks Sayamindu -- Sayamindu Dasgupta [http://sayamindu.randomink.org/ramblings] _______________________________________________ Sugar mailing list [email protected] http://lists.laptop.org/listinfo/sugar
