On 12/01/17 13:53, Pierre Ossman wrote: > > For small updates I see performance growing logarithmically, measured in > pixels/second. At around 500k pixels it starts leveling off at ~1.5 > Gpixels/second. After that the performance starts dropping linearly as > the update grows.
I'll answer myself here... This seems to be a CPU cache issue. Below this limit I see: 4,469,985 cache-misses:u # 0.336 % of all cache refs 35,279,259,258 instructions:u # 1.70 insn per cycle (100.00%) Above the limit I get: 194,571,782 cache-misses:u # 30.322 % of all cache refs 18,084,891,734 instructions:u # 0.73 insn per cycle So no wonder things take a turn for the worse. I'll have to think a bit on how to make this more efficient. Ideas are always welcome. Regards -- Pierre Ossman Software Development Cendio AB https://cendio.com Teknikringen 8 https://twitter.com/ThinLinc 583 30 Linköping https://facebook.com/ThinLinc Phone: +46-13-214600 https://plus.google.com/+CendioThinLinc A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? _______________________________________________ xorg-devel@lists.x.org: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: https://lists.x.org/mailman/listinfo/xorg-devel