2009-01-22, 20:05
I realized some notable difference in running ffplay on Hardy or Intrepid.
Running the same code on Hardy and Intrepid there is one library which is used on Intrepid but not used on Hardy:
librt.so.1
Does anyone know what this is used for ? Why is it not used on Hardy and why used on Intrepid ?
Could this point to some difference why we are having bad performance on Intrepid.
I found out anyway that it does not matter if the loads are balanced or not over the cores. What matters is that the sum of the two core utilization seem to be under 100-120% under Intrepid while on Hardy it is somewhere 170-190% under full load.
So it is not the lack of multithreading or multi core usage we have but the problem is that the video decoding threads are running sequential: somehow the data exchange between the threads is not working properly and one thread waits for the other thread to be ready and so on.
If we could know more about the way this CABAC patch working form Devs we could maybe move foreward to test further things.
Running the same code on Hardy and Intrepid there is one library which is used on Intrepid but not used on Hardy:
librt.so.1
Does anyone know what this is used for ? Why is it not used on Hardy and why used on Intrepid ?
Could this point to some difference why we are having bad performance on Intrepid.
I found out anyway that it does not matter if the loads are balanced or not over the cores. What matters is that the sum of the two core utilization seem to be under 100-120% under Intrepid while on Hardy it is somewhere 170-190% under full load.
So it is not the lack of multithreading or multi core usage we have but the problem is that the video decoding threads are running sequential: somehow the data exchange between the threads is not working properly and one thread waits for the other thread to be ready and so on.
If we could know more about the way this CABAC patch working form Devs we could maybe move foreward to test further things.