On Tue, 17 May 2016, Andi Kleen wrote: > From: Andi Kleen <[email protected]> > > Linux pre-allocates the task structs of the idle tasks for all possible CPUs. > This currently means they all end up on node 0. This also implies > that the cache line of MWAIT, which is around the flags field in the task > struct, are all located in node 0. > > We see a noticeable performance improvement on Knights Landing CPUs when > the cache lines used for MWAIT are located in the local nodes of the CPUs > using them. I would expect this to give a (likely slight) improvement > on other systems too. > > The patch implements placing the idle task in the node of > its CPUs, by passing the right target node to copy_process() > > Signed-off-by: Andi Kleen <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
