Re: [RFC][PATCH RT 0/4] sched/rt: Lower rq lock contention latencies on many CPU boxes

On Fri, 07 Dec 2012 18:56:15 -0500 Steven Rostedt wrote: > I've been debugging large latencies on a 40 core box and found a major > cause due to the thundering herd like grab of the rq lock due to the > pull_rt_task() logic. > > Basically, if a large number of CPUs were to lower its priority rou

[RFC][PATCH RT 0/4] sched/rt: Lower rq lock contention latencies on many CPU boxes

I've been debugging large latencies on a 40 core box and found a major cause due to the thundering herd like grab of the rq lock due to the pull_rt_task() logic. Basically, if a large number of CPUs were to lower its priority roughly the same time, they would all trigger a pull. If there happens t