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authorBen Blum <bblum@google.com>2009-09-23 15:56:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-24 07:20:58 -0700
commitbe367d09927023d081f9199665c8500f69f14d22 (patch)
treef0c5b9da037506da3c5890cf11b51b39a7d3c427 /kernel/sched.c
parentc378369d8b4fa516ff2b1e79c3eded4e0e955ebb (diff)
downloadlwn-be367d09927023d081f9199665c8500f69f14d22.tar.gz
lwn-be367d09927023d081f9199665c8500f69f14d22.zip
cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time
Alter the ss->can_attach and ss->attach functions to be able to deal with a whole threadgroup at a time, for use in cgroup_attach_proc. (This is a pre-patch to cgroup-procs-writable.patch.) Currently, new mode of the attach function can only tell the subsystem about the old cgroup of the threadgroup leader. No subsystem currently needs that information for each thread that's being moved, but if one were to be added (for example, one that counts tasks within a group) this bit would need to be reworked a bit to tell the subsystem the right information. [hidave.darkstar@gmail.com: fix build] Signed-off-by: Ben Blum <bblum@google.com> Signed-off-by: Paul Menage <menage@google.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Matt Helsley <matthltc@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c35
1 files changed, 32 insertions, 3 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 2f76e06bea58..0d0361b9dbb3 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -10377,8 +10377,7 @@ cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
}
static int
-cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct task_struct *tsk)
+cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
{
#ifdef CONFIG_RT_GROUP_SCHED
if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk))
@@ -10388,15 +10387,45 @@ cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
if (tsk->sched_class != &fair_sched_class)
return -EINVAL;
#endif
+ return 0;
+}
+static int
+cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+ struct task_struct *tsk, bool threadgroup)
+{
+ int retval = cpu_cgroup_can_attach_task(cgrp, tsk);
+ if (retval)
+ return retval;
+ if (threadgroup) {
+ struct task_struct *c;
+ rcu_read_lock();
+ list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
+ retval = cpu_cgroup_can_attach_task(cgrp, c);
+ if (retval) {
+ rcu_read_unlock();
+ return retval;
+ }
+ }
+ rcu_read_unlock();
+ }
return 0;
}
static void
cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct cgroup *old_cont, struct task_struct *tsk)
+ struct cgroup *old_cont, struct task_struct *tsk,
+ bool threadgroup)
{
sched_move_task(tsk);
+ if (threadgroup) {
+ struct task_struct *c;
+ rcu_read_lock();
+ list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
+ sched_move_task(c);
+ }
+ rcu_read_unlock();
+ }
}
#ifdef CONFIG_FAIR_GROUP_SCHED