Messages in this thread |  | | From | Greg Thelen <> | | Date | Wed, 21 Sep 2011 23:00:18 -0700 | | Subject | Re: [PATCH v3 2/7] socket: initial cgroup code. |
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On Wed, Sep 21, 2011 at 11:59 AM, Glauber Costa <glommer@parallels.com> wrote: > Right now I am working under the assumption that tasks are long lived inside > the cgroup. Migration potentially introduces some nasty locking problems in > the mem_schedule path. > > Also, unless I am missing something, the memcg already has the policy of > not carrying charges around, probably because of this very same complexity. > > True that at least it won't EBUSY you... But I think this is at least a way > to guarantee that the cgroup under our nose won't disappear in the middle of > our allocations.
Here's the memcg user page behavior using the same pattern:
1. user page P is allocate by task T in memcg M1 2. T is moved to memcg M2. The P charge is left behind still charged to M1 if memory.move_charge_at_immigrate=0; or the charge is moved to M2 if memory.move_charge_at_immigrate=1. 3. rmdir M1 will try to reclaim P (if P was left in M1). If unable to reclaim, then P is recharged to parent(M1).
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