Effects of adjusting coherent_pool kernel parameter value
02-12-2021, 03:13 PM
coherent_pool=0 just sets the initial value to zero. It will be increased as needed afterward. So there is no surprise that the current values are larger than 0.
The setting on the command line probably just old. It probably predates the kernel's ability to increase the atomic coherent dma pool. Maybe someone needed it for the old binary blob GPU driver before panfrost? Or maybe it does nothing, someone read about it helping stability and added it, even though in reality it accomplished nothing. And then it stays there because no one knows why it's there and if it's safe to remove it.
The setting on the command line probably just old. It probably predates the kernel's ability to increase the atomic coherent dma pool. Maybe someone needed it for the old binary blob GPU driver before panfrost? Or maybe it does nothing, someone read about it helping stability and added it, even though in reality it accomplished nothing. And then it stays there because no one knows why it's there and if it's safe to remove it.
