The current debug controller is vaguely called an "Example controller" at the Kconfig prompt, and it is just not that useful for debugging purpose.
This patchset aims to make the debug controller useful again for debugging the cgroup core, especially for cgroup v2 and the thread mode support. This patchset is based on top of the Tejun's cgroup v2 thread mode patchset: https://lkml.org/lkml/2017/6/10/93 which is available in the following git branch. git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git review-cgroup2-threads-v2 Patch 1 adds a new field to css_set to make accurate count of the number of tasks in a css_set. Patch 2 moves the existing debug controller code in cgroup-v1.c into a new debug.c file. Patch 3 changes the Kconfig prompt to "Debug controller". Patch 4 enhances the debug information displayed by the debug controller to make them more useful for debugging purpose. Patch 5 hides the debug control files of the debug controller unless the "cgroup_debug" kernel command line option is specified. Waiman Long (5): cgroup: Keep accurate count of tasks in each css_set cgroup: Move debug cgroup to its own file cgroup: Make Kconfig prompt of debug cgroup more accurate cgroup: Make debug cgroup support v2 and thread mode cgroup: Enable debug controller only with cgroup_debug boot option include/linux/cgroup-defs.h | 3 + init/Kconfig | 7 +- kernel/cgroup/Makefile | 1 + kernel/cgroup/cgroup-internal.h | 2 + kernel/cgroup/cgroup-v1.c | 155 +----------------- kernel/cgroup/cgroup.c | 12 +- kernel/cgroup/debug.c | 342 ++++++++++++++++++++++++++++++++++++++++ 7 files changed, 366 insertions(+), 156 deletions(-) create mode 100644 kernel/cgroup/debug.c -- 1.8.3.1
