The reason why webGL produces so many minor page faults?

I'm studying linux kernel, but I don't know much about web.
I saw some WebGL samples on browser(http://webglsamples.org/), and I tested it with perf, which is performance analysis tool of linux.
What I saw was excessive number of minor page faults(about 10000~100000).
I traced these minor page faults and found that these faults occurs when accessing the allocated memory space for the first time.
This means WebGL applications repeatedly do following process.
1. Allocate memory space
2. Do computation
3. Free memory space

I'm trying to analyze the reason of these phenomenon.
But I know nothing about web environment, java script, and something like that... Anyone can give some hints about this?
Why does WebGL application excessively repeat allocate/free memory space?