On Fri 17-01-14 13:11:54, Tejun Heo wrote: > 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. > > Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Li Zefan <lizefan@xxxxxxxxxx> > Cc: Johannes Weiner <hannes@xxxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxx> > Cc: Balbir Singh <bsingharora@xxxxxxxxx> > Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > Cc: Aristeu Rozanski <aris@xxxxxxxxxx> > Cc: Serge E. Hallyn <serue@xxxxxxxxxx> > Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> > Cc: Vivek Goyal <vgoyal@xxxxxxxxxx> > Cc: Neil Horman <nhorman@xxxxxxxxxxxxx> > Cc: Thomas Graf <tgraf@xxxxxxx> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> For memcg and hugetlb Acked-by: Michal Hocko <mhocko@xxxxxxx> [...] Thanks! -- Michal Hocko SUSE Labs -- 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
