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authorBalbir Singh <balbir@linux.vnet.ibm.com>2008-02-07 00:13:54 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-07 08:42:18 -0800
commit67e465a77ba658635309ee00b367bec6555ea544 (patch)
tree172060de1a91624725215c5f0e1131ce5e5c5e92 /mm/memcontrol.c
parent8a9f3ccd24741b50200c3f33d62534c7271f3dfc (diff)
Memory controller: task migration
Allow tasks to migrate from one cgroup to the other. We migrate mm_struct's mem_cgroup only when the thread group id migrates. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memcontrol.c')
-rw-r--r--mm/memcontrol.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ebca767292d..b25df2a9d02 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -326,11 +326,46 @@ static int mem_cgroup_populate(struct cgroup_subsys *ss,
ARRAY_SIZE(mem_cgroup_files));
}
+static void mem_cgroup_move_task(struct cgroup_subsys *ss,
+ struct cgroup *cont,
+ struct cgroup *old_cont,
+ struct task_struct *p)
+{
+ struct mm_struct *mm;
+ struct mem_cgroup *mem, *old_mem;
+
+ mm = get_task_mm(p);
+ if (mm == NULL)
+ return;
+
+ mem = mem_cgroup_from_cont(cont);
+ old_mem = mem_cgroup_from_cont(old_cont);
+
+ if (mem == old_mem)
+ goto out;
+
+ /*
+ * Only thread group leaders are allowed to migrate, the mm_struct is
+ * in effect owned by the leader
+ */
+ if (p->tgid != p->pid)
+ goto out;
+
+ css_get(&mem->css);
+ rcu_assign_pointer(mm->mem_cgroup, mem);
+ css_put(&old_mem->css);
+
+out:
+ mmput(mm);
+ return;
+}
+
struct cgroup_subsys mem_cgroup_subsys = {
.name = "memory",
.subsys_id = mem_cgroup_subsys_id,
.create = mem_cgroup_create,
.destroy = mem_cgroup_destroy,
.populate = mem_cgroup_populate,
+ .attach = mem_cgroup_move_task,
.early_init = 1,
};