From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Aneesh Kumar K.V" Subject: Re: [PATCH -V8 15/16] hugetlb/cgroup: migrate hugetlb cgroup info from oldpage to new page during migration Date: Mon, 11 Jun 2012 15:47:28 +0530 Message-ID: <878vfu5f0n.fsf@skywalker.in.ibm.com> References: <1339232401-14392-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1339232401-14392-16-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20120611092424.GJ12402@tiehlicka.suse.cz> Mime-Version: 1.0 Return-path: In-Reply-To: <20120611092424.GJ12402-VqjxzfR4DlwKmadIfiO5sKVXKuFTiq87@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Michal Hocko Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org, dhillf-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, rientjes-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Michal Hocko writes: > On Sat 09-06-12 14:30:00, Aneesh Kumar K.V wrote: >> From: "Aneesh Kumar K.V" >> >> With HugeTLB pages, hugetlb cgroup is uncharged in compound page >> destructor. Since we are holding a hugepage reference, > > Who is holding that reference? I do not see anybody calling get_page in > this patch... > soft_offline_huge_page takes the reference. It does the final put_page(hpage) there. >> we can be sure that old page won't get uncharged till the last >> put_page(). >> -aneesh