Michal Hocko <mhocko@suse.cz> writes:

> On Wed 28-03-12 23:09:34, Aneesh Kumar K.V wrote:
>> Michal Hocko <mhocko@suse.cz> writes:
>> 
>> > On Fri 16-03-12 23:09:25, Aneesh Kumar K.V wrote:
>> >> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>> >> 
>> >> This adds necessary charge/uncharge calls in the HugeTLB code
>> >
>> > This begs for more description...
>> > Other than that it looks correct.
>> >
>> 
>> Updated as below
>> 
>>     hugetlb: add charge/uncharge calls for HugeTLB alloc/free
>> 
>>     This adds necessary charge/uncharge calls in the HugeTLB code. We do
>>     memcg charge in page alloc and uncharge in compound page destructor.
>>     We also need to ignore HugeTLB pages in __mem_cgroup_uncharge_common
>>     because that get called from delete_from_page_cache
>
> and from mem_cgroup_end_migration used during soft_offline_page.
>
> Btw., while looking at mem_cgroup_end_migration, I have noticed that you
> need to take care of mem_cgroup_prepare_migration as well otherwise the
> page would get charged as a normal (shmem) page.
>

Won't we skip HugeTLB pages in migrate ? check_range do check for
is_vm_hugetlb_page.

-aneesh