NUMA is where the fun starts. If I wish to adjust a group of processes bound only to a NUMA group of cpus. It should not be required to disrupt other cpus. Init system controlling the cgroups is also sounding trouble. Why we don't want to write like 1 000 000 different interfaces to talk to cgroups. Items like chromuim browser might wish to use cgroups in future to lets say contain flash. Best solution to the problems not a library or in the init system its a form of userspace driver. The userspace driver has the permissions to alter and change cgroups and possible no right todo anything else in final form. Why not part of the init binary. Lets say you have 1000 processors. And for some reason you are running something that tweaking cgroups a lot. You don't want to stall all 1000 processes if it not required. Single process could cause this. What ever in in change of the cgroups has to be massively multi threaded. Also has to be changeable based on NUMA requirements of the system at times. You don't want to have to be editing the core of init system or reboot the system just to change the cgroup management system to be more compatible with current hardware. This is again why userspace driver. You can stop the driver and start another one if required. While still maintaining the rule of only 1 active at any 1 time. If someone can load a kernel driver any how the can cause hell. Single process is not going to work because this will require stopping all cpus. What is required is single processes/theads. Going the userspace driver solution emulation of the old cgroup system could be pushed into userspace. So removing old code from the core and allow rejecting of hazard changes to be applied to the old method without having to update kernel every time. If there is an requirement to change the interface in future its less problem. If kbus (kernel dbus) was already done I would be tempted to place this as a default feature on the kbus. This would not be dependant on any particular init system. Since kbus is not ready creating a text device to receive messages for now would be a suitable solution in my eyes. Peter Dolding _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
