linux_dsm_epyc7002/kernel/sched
Tejun Heo eb95419b02 cgroup: pass around cgroup_subsys_state instead of cgroup in subsystem methods
cgroup is currently in the process of transitioning to using struct
cgroup_subsys_state * as the primary handle instead of struct cgroup *
in subsystem implementations for the following reasons.

* With unified hierarchy, subsystems will be dynamically bound and
  unbound from cgroups and thus css's (cgroup_subsys_state) may be
  created and destroyed dynamically over the lifetime of a cgroup,
  which is different from the current state where all css's are
  allocated and destroyed together with the associated cgroup.  This
  in turn means that cgroup_css() should be synchronized and may
  return NULL, making it more cumbersome to use.

* Differing levels of per-subsystem granularity in the unified
  hierarchy means that the task and descendant iterators should behave
  differently depending on the specific subsystem the iteration is
  being performed for.

* In majority of the cases, subsystems only care about its part in the
  cgroup hierarchy - ie. the hierarchy of css's.  Subsystem methods
  often obtain the matching css pointer from the cgroup and don't
  bother with the cgroup pointer itself.  Passing around css fits
  much better.

This patch converts all cgroup_subsys methods to take @css instead of
@cgroup.  The conversions are mostly straight-forward.  A few
noteworthy changes are

* ->css_alloc() now takes css of the parent cgroup rather than the
  pointer to the new cgroup as the css for the new cgroup doesn't
  exist yet.  Knowing the parent css is enough for all the existing
  subsystems.

* In kernel/cgroup.c::offline_css(), unnecessary open coded css
  dereference is replaced with local variable access.

This patch shouldn't cause any behavior differences.

v2: Unnecessary explicit cgrp->subsys[] deref in css_online() replaced
    with local variable @css as suggested by Li Zefan.

    Rebased on top of new for-3.12 which includes for-3.11-fixes so
    that ->css_free() invocation added by da0a12caff ("cgroup: fix a
    leak when percpu_ref_init() fails") is converted too.  Suggested
    by Li Zefan.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Aristeu Rozanski <aris@redhat.com>
Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Steven Rostedt <rostedt@goodmis.org>
2013-08-08 20:11:23 -04:00
..
auto_group.c sched/autogroup: Fix race with task_groups list 2013-05-28 09:40:22 +02:00
auto_group.h Revert "sched/autogroup: Fix crash on reboot when autogroup is disabled" 2012-12-11 10:23:45 +01:00
clock.c sched_clock: Prevent 64bit inatomicity on 32bit systems 2013-04-08 11:50:44 +02:00
core.c cgroup: pass around cgroup_subsys_state instead of cgroup in subsystem methods 2013-08-08 20:11:23 -04:00
cpuacct.c cgroup: pass around cgroup_subsys_state instead of cgroup in subsystem methods 2013-08-08 20:11:23 -04:00
cpuacct.h sched/cpuacct: Initialize root cpuacct earlier 2013-04-10 13:54:20 +02:00
cpupri.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
cpupri.h sched: Move all scheduler bits into kernel/sched/ 2011-11-17 12:20:22 +01:00
cputime.c Linux 3.10 2013-07-01 11:18:53 +02:00
debug.c sched/debug: Remove CONFIG_FAIR_GROUP_SCHED mask 2013-06-28 13:17:17 +02:00
fair.c sched/fair: Fix typo describing flags in enqueue_entity 2013-06-27 10:18:25 +02:00
features.h mutex: Move mutex spinning code from sched/core.c back to mutex.c 2013-04-19 09:33:34 +02:00
idle_task.c sched: Keep at least 1 tick per second for active dynticks tasks 2013-05-04 08:32:02 +02:00
Makefile sched: Factor out load calculation code from sched/core.c --> sched/proc.c 2013-05-07 13:14:50 +02:00
proc.c sched: Change get_rq_runnable_load() to static and inline 2013-06-27 10:07:44 +02:00
rt.c sched/rt: Simplify pull_rt_task() logic and remove .leaf_rt_rq_list 2013-06-19 12:58:40 +02:00
sched.h cgroup: s/cgroup_subsys_state/cgroup_css/ s/task_subsys_state/task_css/ 2013-08-08 20:11:22 -04:00
stats.c fix a leak in /proc/schedstats 2013-04-29 15:41:45 -04:00
stats.h Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-07-06 14:09:38 -07:00
stop_task.c sched: Use an accessor to read the rq clock 2013-05-28 09:40:27 +02:00