Buffer mapping blocked Warning

can someone please guide what is this and how can i resolve it
[warning] [buffer] Performance warning. Buffer mapping blocked: 0.021

i’m using CG Server 2.1 on HP z820(Xeon 16 Core, 32GB RAM, Quadro k4000) and i’m getting this warning

This is a warning. The code related to this was removed in 2.2. The warning is displayed if it takes more than 20ms to execute a buffer mapping call. But given your configuration I’m a bit surprised you are seeing it, are you running the latest drivers for the Quadro? And are you running the channel at 50fps or higher?

yes, latest driver installed for graphics and decklink.
using 1080i5000 Channel and playing some rendered alpha mov(format 1080i) and playing scroll and Lowerthirds with HTML at same time

but sometime i get this warning on single alpha loaded mov file at 1080i