> It seems strange to me to add such policies to the kernel. > Addmittingly, documentation of some settings is non-existent and one needs > various different tools to set this (sysctl, procfs, sysfs, ethtool, etc).
The problem is that different applications need different policies. The only entity which can efficiently negotiate between different applications' conflicting requests is the kernel. And that is pretty much the basic job description of a kernel: multiplex hardware efficiently between different users. So yes the user space tuning approach works for simple cases ("only run workloads that require the same tuning"), but is ultimately not very interesting nor scalable. -Andi