On Fri 30-03-12 16:10:00, Aneesh Kumar K.V wrote:
> 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 ?

Yes but we still migrate for memory failure (see soft_offline_page).

> check_range do check for is_vm_hugetlb_page.
> 
> -aneesh
> 

-- 
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
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Czech Republic