Hi, v8 of a series of patches, originally authored by Mathieu, with the intent of fixing a long standing issue of SCHED_DEADLINE bandwidth accounting. As originally reported by Steve [1], when hotplug and/or (certain) cpuset reconfiguration operations take place, DEADLINE bandwidth accounting information is lost since root domains are destroyed and recreated. Mathieu's approach is based on restoring bandwidth accounting info on the newly created root domains by iterating through the (DEADLINE) tasks belonging to the configured cpuset(s). Apart from the usual rebase on top of cgroup/for-next, this version brings in an important difference w.r.t. v7: cpuset_mutex conversion to percpu_rwsem (as suggested by Peter) to deal with a performance regression caused by the fact that grabbing the (v7) callback_lock raw spinlock from sched_setscheduler() was in fact a bottleneck. The conversion required some lock order changes and an rcu related mod. So, this is (unfortunately) more than a small update. Hope it still makes sense, though. Set also available at https://github.com/jlelli/linux.git fixes/deadline/root-domain-accounting-v8 Thanks, - Juri [1] https://lkml.org/lkml/2016/2/3/966 Juri Lelli (6): cpuset: Rebuild root domain deadline accounting information sched/deadline: Fix bandwidth accounting at all levels after offline migration cgroup/cpuset: convert cpuset_mutex to percpu_rwsem cgroup/cpuset: Change cpuset_rwsem and hotplug lock order sched/core: Prevent race condition between cpuset and __sched_setscheduler() rcu/tree: Setschedule gp ktread to SCHED_FIFO outside of atomic region Mathieu Poirier (2): sched/topology: Adding function partition_sched_domains_locked() sched/core: Streamlining calls to task_rq_unlock() include/linux/cgroup.h | 1 + include/linux/cpuset.h | 13 ++- include/linux/sched.h | 5 + include/linux/sched/deadline.h | 8 ++ include/linux/sched/topology.h | 10 ++ kernel/cgroup/cgroup.c | 2 +- kernel/cgroup/cpuset.c | 163 +++++++++++++++++++++++++-------- kernel/rcu/tree.c | 6 +- kernel/sched/core.c | 57 ++++++++---- kernel/sched/deadline.c | 63 +++++++++++++ kernel/sched/sched.h | 3 - kernel/sched/topology.c | 30 +++++- 12 files changed, 290 insertions(+), 71 deletions(-) -- 2.17.2
