That is, most probably in this driver new synching added (that solves prev bugs) but this synching implemented as CPU busy-wait loops that show themselves when app calls any or some blocking OpenCL functions.
Not sure whether your assumption is right or not. If so, may be someone from the driver team may help to answer those questions. I'll check and get back to you.
BTW, its nice to hear that your problem has been resolved. Thanks for the confirmation.
Yes, it's only assumption but based on some measures between different versions of driver.
Would be good to get some info regarding that CPU time increase from driver team.
And especially useful would be to get some hints how to avoid it. Our applications use both CPU and GPU for computations so we can't sacrifice CPU performance w/o losses.