Hello, This is v3 of cgroup2 thread mode patchset. The changes from v2[L] are * Switched to marking each cgroup threaded instead of doing it per-subtree as suggested by PeterZ. This allows more flexibility and removes certain interface quirks. * Dropped RFC tag and excluded cpu controller patches from this patchset as threaded mode behaviors can easily be verified with the pid controller. Will follow up with cpu controller patchset later. It is largely based on the discussions that we had at the plumbers last year. Here's the rough outline. * Thread mode is explicitly enabled on a cgroup by writing "threaded" into "cgroup.type" file. The cgroup shouldn't have any processes or child cgroups. A threaded cgroup joins the the parent's resource domain and becomes a part of the threaded subtree anchored at the nearest domain ancestor, which is called the threaded domain cgroup of the subtree. * Threads can be put anywhere in a threaded subtree by writing TIDs into "cgroup.threads" file. Process granularity and no-internal-process constraint don't apply in a threaded subtree. * To be used in a threaded subtree, controllers should explicitly declare thread mode support and should be able to handle internal competition in some way. * The threaded domain cgroup of a threaded subtree serves as the resource domain for the whole subtree. This is where all the controllers are guaranteed to have a common ground and resource consumptions in the threaded subtree which aren't tied to a specific thread are charged. Non-threaded controllers never see beyond thread root and can assume that all controllers will follow the same rules upto that point. * Unlike other cgroups, the system root cgroup can serve as parent to domain child cgroups and threaded domains to threaded subtrees. This allows threaded controllers to implement thread granular resource control without getting in the way of system level resource partitioning. For more details on the interface and behavior, please refer to 0005. This patchset contains the following six patches. 0001-cgroup-reorganize-cgroup.procs-task-write-path.patch 0002-cgroup-add-flags-to-css_task_iter_start-and-implemen.patch 0003-cgroup-introduce-cgroup-dom_cgrp-and-threaded-css_se.patch 0004-cgroup-implement-CSS_TASK_ITER_THREADED.patch 0005-cgroup-implement-cgroup-v2-thread-support.patch 0006-cgroup-update-debug-controller-to-print-out-thread-m.patch 0001-0005 implement cgroup2 thread mode. 0006 enables debug controller on it. The patchset is based on the current cgroup/for-4.14 27f26753f8c0 ("cgroup: replace css_set walking populated test with testing cgrp->nr_populated_csets") and also available in the following git branch. git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git review-cgroup2-threads-v3 diffstat follows. Documentation/cgroup-v2.txt | 181 +++++++++- include/linux/cgroup-defs.h | 45 ++ include/linux/cgroup.h | 15 kernel/cgroup/cgroup-internal.h | 12 kernel/cgroup/cgroup-v1.c | 69 +++ kernel/cgroup/cgroup.c | 712 +++++++++++++++++++++++++++++++--------- kernel/cgroup/cpuset.c | 6 kernel/cgroup/debug.c | 58 ++- kernel/cgroup/freezer.c | 6 kernel/cgroup/pids.c | 1 kernel/events/core.c | 1 mm/memcontrol.c | 2 net/core/netclassid_cgroup.c | 2 13 files changed, 906 insertions(+), 204 deletions(-) Thanks. -- tejun [L] http://lkml.kernel.org/r/20170610140351.10703-1-tj@xxxxxxxxxx -- 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