Actually my problem is es2gear only shows 50fps, glmark-es2 also experience a low fps rate
my kernel boot arguments is
sunxi_g2d_mem_reserve=16
sunxi_no_mali_mem_reserve
sunxi_fb_mem_reserve=32
and sunxi-mali test is showing that render is MALI400MP and display a triangle properly.
es2_info is also showing that render is MALI400MP
but I still can't get a correct fps rate and cpu usage is 100%