On Mon, 2014-01-06 at 13:17 +0100, Peter Zijlstra wrote: > On Fri, Dec 27, 2013 at 06:22:31PM +0800, Wanpeng Li wrote: > > We have a server which have 200 CPUs and 8G memory, there is auto_group creation > > I'm hoping that is 8T, otherwise that's a severely under provisioned > system, that's a mere 40M per cpu, does that even work? > > > which will almost consume 12MB memory even if add 'noautogroup' in the kernel > > boot parameter. In addtion, SLUB per cpu partial caches freeing that is local to > > a processor which requires the taking of locks at the price of more indeterminism > > in the latency of the free. This patch fix it by check noautogroup earlier to avoid > > free after unnecessary memory consumption. > > That's just a bad changelog. It fails to explain the actual problem and > it babbles about unrelated things like SLUB details. > > Also, I'm not entirely sure what the intention was of this code, I've so > far tried to ignore the entire autogroup fest... > > It looks like it creates and maintains the entire autogroup hierarchy, > such that if you at runtime enable the sysclt and move tasks 'back' to > the root cgroup you get the autogroup behaviour. > > Was this intended? Mike? Yeah, it was intended that autogroups always exist if you config it in. We could make is such that noautogroup makes it irreversibly off/dead. People with 200 ram starved CPUs can turn it off in their .config too :) -Mike -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>