Hi, This is regarding SurfaceFlinger’s performance. If you think I have a point here please let me know.
I have observed during my Camera application SurfaceFlinger consumes too much of cpu (>80%). Tried to know its cause, its found out that it is actually drawing the “clip” region twice consecutively. By drawing twice I mean, the coordinates values are same for the 2 clip regions which gets drawn in sequence. The “clip” region is calculated from Layer’s visibleRegion and dirty region. So in this case 2 layers in the currentstate are such that they are calculating similar clip region. I tried a hack not to draw the clip twice in SurfaceFlinger::composeSurfaces() if it has same coordinates value, before it calls layer->draw(clip) . It worked with no visible side effects and cpu performance improved. That makes me think that it might be a bug or scope of improvement in surfaceflinger. Log showing 2 consecutive Layers calculating same region to draw: E/SurfaceFlinger( 976): + LayerBuffer 0x3b3920 E/SurfaceFlinger( 976): z= 21010 D/Region ( 976): Region visibleRegionScreen (this=0x3b3930, count=1) D/Region ( 976): [ 32, 26, 208, 261] D/Region ( 976): Region clipDUMP (this=0x44fa19c4, count=1) D/Region ( 976): [ 32, 26, 208, 261] E/SurfaceFlinger( 976): composeSurfaces layer->draw() E/SurfaceFlinger( 976): + Layer 0x3e3110 E/SurfaceFlinger( 976): z= 21015 D/Region ( 976): Region visibleRegionScreen (this=0x3e3120, count=1) D/Region ( 976): [ 0, 0, 240, 320] D/Region ( 976): Region clipDUMP (this=0x44fa19c4, count=1) D/Region ( 976): [ 32, 26, 208, 261] E/SurfaceFlinger( 976): composeSurfaces layer->draw() Any suggestions will be highly appreaciated.. Thanks, Naruka -- unsubscribe: android-porting+unsubscr...@googlegroups.com website: http://groups.google.com/group/android-porting
