This example subsystem exports debugging information as an aid to diagnosing refcount leaks, etc, in the container framework. Signed-off-by: Paul Menage --- include/linux/container_subsys.h | 4 + init/Kconfig | 10 ++++ kernel/Makefile | 1 kernel/container_debug.c | 89 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 104 insertions(+) Index: container-2.6.22-rc2-mm1/include/linux/container_subsys.h =================================================================== --- container-2.6.22-rc2-mm1.orig/include/linux/container_subsys.h +++ container-2.6.22-rc2-mm1/include/linux/container_subsys.h @@ -19,4 +19,8 @@ SUBSYS(cpuset) /* */ +#ifdef CONFIG_CONTAINER_DEBUG +SUBSYS(debug) +#endif + /* */ Index: container-2.6.22-rc2-mm1/init/Kconfig =================================================================== --- container-2.6.22-rc2-mm1.orig/init/Kconfig +++ container-2.6.22-rc2-mm1/init/Kconfig @@ -306,6 +306,16 @@ config LOG_BUF_SHIFT config CONTAINERS bool +config CONTAINER_DEBUG + bool "Example debug container subsystem" + select CONTAINERS + help + This option enables a simple container subsystem that + exports useful debugging information about the containers + framework + + Say N if unsure + config CPUSETS bool "Cpuset support" depends on SMP Index: container-2.6.22-rc2-mm1/kernel/container_debug.c =================================================================== --- /dev/null +++ container-2.6.22-rc2-mm1/kernel/container_debug.c @@ -0,0 +1,89 @@ +/* + * kernel/ccontainer_debug.c - Example container subsystem that + * exposes debug info + * + * Copyright (C) Google Inc, 2007 + * + * Developed by Paul Menage (menage@google.com) + * + */ + +#include +#include + +static int debug_create(struct container_subsys *ss, struct container *cont) +{ + struct container_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL); + if (!css) + return -ENOMEM; + cont->subsys[debug_subsys_id] = css; + return 0; +} + +static void debug_destroy(struct container_subsys *ss, struct container *cont) +{ + kfree(cont->subsys[debug_subsys_id]); +} + +static u64 container_refcount_read(struct container *cont, struct cftype *cft) +{ + return atomic_read(&cont->count); +} + +static u64 taskcount_read(struct container *cont, struct cftype *cft) +{ + u64 count; + container_lock(); + count = container_task_count(cont); + container_unlock(); + return count; +} + +static u64 current_css_group_read(struct container *cont, struct cftype *cft) +{ + return (u64) current->containers; +} + +static u64 current_css_group_refcount_read(struct container *cont, + struct cftype *cft) +{ + u64 count; + rcu_read_lock(); + count = atomic_read(¤t->containers->ref.refcount); + rcu_read_unlock(); + return count; +} + +static struct cftype files[] = { + { + .name = "debug.container_refcount", + .read_uint = container_refcount_read, + }, + { + .name = "debug.taskcount", + .read_uint = taskcount_read, + }, + + { + .name = "debug.current_css_group", + .read_uint = current_css_group_read, + }, + + { + .name = "debug.current_css_group_refcount", + .read_uint = current_css_group_refcount_read, + }, +}; + +static int debug_populate(struct container_subsys *ss, struct container *cont) +{ + return container_add_files(cont, files, ARRAY_SIZE(files)); +} + +struct container_subsys debug_subsys = { + .name = "debug", + .create = debug_create, + .destroy = debug_destroy, + .populate = debug_populate, + .subsys_id = debug_subsys_id, +}; Index: container-2.6.22-rc2-mm1/kernel/Makefile =================================================================== --- container-2.6.22-rc2-mm1.orig/kernel/Makefile +++ container-2.6.22-rc2-mm1/kernel/Makefile @@ -37,6 +37,7 @@ obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o obj-$(CONFIG_KEXEC) += kexec.o obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_CONTAINERS) += container.o +obj-$(CONFIG_CONTAINER_DEBUG) += container_debug.o obj-$(CONFIG_CPUSETS) += cpuset.o obj-$(CONFIG_CONTAINER_CPUACCT) += cpu_acct.o obj-$(CONFIG_IKCONFIG) += configs.o -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/