On Fri, 25 Nov 2011 15:38:16 -0200Hi Kame,
Glauber Costa<glommer@xxxxxxxxxxxxx> wrote:
Since this code is still experimental, we are leaving the exact
details of how to move tasks between cgroups when kernel memory
accounting is used as future work.
For now, we simply disallow movement if there are any pending
accounted memory.
Signed-off-by: Glauber Costa<glommer@xxxxxxxxxxxxx>
CC: Hiroyouki Kamezawa<kamezawa.hiroyu@xxxxxxxxxxxxxx>
---
mm/memcontrol.c | 23 ++++++++++++++++++++++-
1 files changed, 22 insertions(+), 1 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2df5d3c..ab7e57b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5451,10 +5451,19 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
{
int ret = 0;
struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup);
+ struct mem_cgroup *from = mem_cgroup_from_task(p);
+
+#if defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM)&& defined(CONFIG_INET)
+ if (from != mem&& !mem_cgroup_is_root(from)&&
+ res_counter_read_u64(&from->tcp_mem.tcp_memory_allocated, RES_USAGE)) {
+ printk(KERN_WARNING "Can't move tasks between cgroups: "
+ "Kernel memory held. task: %s\n", p->comm);
+ return 1;
+ }
+#endif
Hmm, the kernel memory is not guaranteed as being held by the 'task' ?
How about
"Now, moving task between cgroup is disallowed while the source cgroup
containes kmem reference." ?
Hmm.. we need to fix this task-move/rmdir issue before production use.
Thanks,
-Kame