From 073219e995b4a3f8cf1ce8228b7ef440b6994ac0 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sat, 8 Feb 2014 10:36:58 -0500 Subject: cgroup: clean up cgroup_subsys names and initialization cgroup_subsys is a bit messier than it needs to be. * The name of a subsys can be different from its internal identifier defined in cgroup_subsys.h. Most subsystems use the matching name but three - cpu, memory and perf_event - use different ones. * cgroup_subsys_id enums are postfixed with _subsys_id and each cgroup_subsys is postfixed with _subsys. cgroup.h is widely included throughout various subsystems, it doesn't and shouldn't have claim on such generic names which don't have any qualifier indicating that they belong to cgroup. * cgroup_subsys->subsys_id should always equal the matching cgroup_subsys_id enum; however, we require each controller to initialize it and then BUG if they don't match, which is a bit silly. This patch cleans up cgroup_subsys names and initialization by doing the followings. * cgroup_subsys_id enums are now postfixed with _cgrp_id, and each cgroup_subsys with _cgrp_subsys. * With the above, renaming subsys identifiers to match the userland visible names doesn't cause any naming conflicts. All non-matching identifiers are renamed to match the official names. cpu_cgroup -> cpu mem_cgroup -> memory perf -> perf_event * controllers no longer need to initialize ->subsys_id and ->name. They're generated in cgroup core and set automatically during boot. * Redundant cgroup_subsys declarations removed. * While updating BUG_ON()s in cgroup_init_early(), convert them to WARN()s. BUGging that early during boot is stupid - the kernel can't print anything, even through serial console and the trap handler doesn't even link stack frame properly for back-tracing. This patch doesn't introduce any behavior changes. v2: Rebased on top of fe1217c4f3f7 ("net: net_cls: move cgroupfs classid handling into core"). Signed-off-by: Tejun Heo Acked-by: Neil Horman Acked-by: "David S. Miller" Acked-by: "Rafael J. Wysocki" Acked-by: Michal Hocko Acked-by: Peter Zijlstra Acked-by: Aristeu Rozanski Acked-by: Ingo Molnar Acked-by: Li Zefan Cc: Johannes Weiner Cc: Balbir Singh Cc: KAMEZAWA Hiroyuki Cc: Serge E. Hallyn Cc: Vivek Goyal Cc: Thomas Graf --- kernel/cgroup_freezer.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'kernel/cgroup_freezer.c') diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index 6c3154e477f6..98ea26a99076 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -52,7 +52,7 @@ static inline struct freezer *css_freezer(struct cgroup_subsys_state *css) static inline struct freezer *task_freezer(struct task_struct *task) { - return css_freezer(task_css(task, freezer_subsys_id)); + return css_freezer(task_css(task, freezer_cgrp_id)); } static struct freezer *parent_freezer(struct freezer *freezer) @@ -84,8 +84,6 @@ static const char *freezer_state_strs(unsigned int state) return "THAWED"; }; -struct cgroup_subsys freezer_subsys; - static struct cgroup_subsys_state * freezer_css_alloc(struct cgroup_subsys_state *parent_css) { @@ -473,13 +471,11 @@ static struct cftype files[] = { { } /* terminate */ }; -struct cgroup_subsys freezer_subsys = { - .name = "freezer", +struct cgroup_subsys freezer_cgrp_subsys = { .css_alloc = freezer_css_alloc, .css_online = freezer_css_online, .css_offline = freezer_css_offline, .css_free = freezer_css_free, - .subsys_id = freezer_subsys_id, .attach = freezer_attach, .fork = freezer_fork, .base_cftypes = files, -- cgit v1.2.2