v7: - Add a root-only cpuset.cpus.isolated control file for CPU isolation. - Enforce that load_balancing can only be turned off on cpusets with CPUs from the isolated list. - Update sched domain generation to allow cpusets with CPUs only from the isolated CPU list to be in separate root domains. v6: - Hide cpuset control knobs in root cgroup. - Rename effective_cpus and effective_mems to cpus.effective and mems.effective respectively. - Remove cpuset.flags and add cpuset.sched_load_balance instead as the behavior of sched_load_balance has changed and so is not a simple flag. - Update cgroup-v2.txt accordingly. v5: - Add patch 2 to provide the cpuset.flags control knob for the sched_load_balance flag which should be the only feature that is essential as a replacement of the "isolcpus" kernel boot parameter. v4: - Further minimize the feature set by removing the flags control knob. v3: - Further trim the additional features down to just memory_migrate. - Update Documentation/cgroup-v2.txt. v6 patch: https://lkml.org/lkml/2018/3/21/530 The purpose of this patchset is to provide a basic set of cpuset features for cgroup v2. This basic set includes the non-root "cpus", "mems", "cpus.effective" and "mems.effective", "sched_load_balance" control file as well as a root-only "cpus.isolated". The root-only "cpus.isolated" file is added to support use cases similar to the "isolcpus" kernel parameter. CPUs from the isolated list can be put into child cpusets where "sched_load_balance" can be disabled to allow finer control of task-cpu mappings of those isolated CPUs. On the other hand, enabling the "sched_load_balance" on a cpuset with only CPUs from the isolated list will allow those CPUs to use a separate root domain from that of the root cpuset. This patchset does not exclude the possibility of adding more features in the future after careful consideration. Patch 1 enables cpuset in cgroup v2 with cpus, mems and their effective counterparts. Patch 2 adds sched_load_balance whose behavior changes in v2 to become hierarchical and includes an implicit !cpu_exclusive. Patch 3 adds a new root-only "cpuset.cpus.isolated" control file for CPU isolation purpose. Patch 4 adds the limitation that "sched_load_balance" can only be turned off in a cpuset if all the CPUs in the cpuset are already in the root's "cpuset.cpus.isolated". Patch 5 modifies the sched domain generation code to generate separate root sched domains if all the CPUs in a cpuset comes from "cpuset.cpus.isolated". In other words, all the CPUs that need to be isolated or in separate root domains have to be put into the "cpuset.cpus.isolated" first. Then child cpusets can be created to partition those isolated CPUs into either separate root domains with "sched_load_balance" on or really isolated CPUs with "sched_load_balance" off. Load balancing cannot be turned off at root. Waiman Long (5): cpuset: Enable cpuset controller in default hierarchy cpuset: Add cpuset.sched_load_balance to v2 cpuset: Add a root-only cpus.isolated v2 control file cpuset: Restrict load balancing off cpus to subset of cpus.isolated cpuset: Make generate_sched_domains() recognize isolated_cpus Documentation/cgroup-v2.txt | 138 ++++++++++++++++++++- kernel/cgroup/cpuset.c | 287 +++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 404 insertions(+), 21 deletions(-) -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
