cgroup: drop @skip_css from cgroup_taskset_for_each()

If !NULL, @skip_css makes cgroup_taskset_for_each() skip the matching
css.  The intention of the interface is to make it easy to skip css's
(cgroup_subsys_states) which already match the migration target;
however, this is entirely unnecessary as migration taskset doesn't
include tasks which are already in the target cgroup.  Drop @skip_css
from cgroup_taskset_for_each().

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Daniel Borkmann <dborkman@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d4cfc5561830..ba386a06ab11 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7600,7 +7600,7 @@ static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css,
 {
         struct task_struct *task;
 
-        cgroup_taskset_for_each(task, css, tset) {
+        cgroup_taskset_for_each(task, tset) {
 #ifdef CONFIG_RT_GROUP_SCHED
                 if (!sched_rt_can_attach(css_tg(css), task))
                         return -EINVAL;
@@ -7618,7 +7618,7 @@ static void cpu_cgroup_attach(struct cgroup_subsys_state *css,
 {
         struct task_struct *task;
 
-        cgroup_taskset_for_each(task, css, tset)
+        cgroup_taskset_for_each(task, tset)
                 sched_move_task(task);
 }