From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Aneesh Kumar K.V" Subject: Re: [PATCH -V8 12/16] hugetlb/cgroup: Add support for cgroup removal Date: Mon, 11 Jun 2012 15:10:20 +0530 Message-ID: <87fwa25gqj.fsf@skywalker.in.ibm.com> References: <1339232401-14392-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1339232401-14392-13-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20120611085258.GD12402@tiehlicka.suse.cz> Mime-Version: 1.0 Return-path: In-Reply-To: <20120611085258.GD12402-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 14:29:57, Aneesh Kumar K.V wrote: >> From: "Aneesh Kumar K.V" >> >> This patch add support for cgroup removal. If we don't have parent >> cgroup, the charges are moved to root cgroup. >> >> Signed-off-by: Aneesh Kumar K.V >> --- >> mm/hugetlb_cgroup.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++-- >> 1 file changed, 79 insertions(+), 2 deletions(-) >> >> diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c >> index 48efd5a..9458fe3 100644 >> --- a/mm/hugetlb_cgroup.c >> +++ b/mm/hugetlb_cgroup.c >> @@ -99,10 +99,87 @@ static void hugetlb_cgroup_destroy(struct cgroup *cgroup) >> kfree(h_cgroup); >> } >> >> + >> +static int hugetlb_cgroup_move_parent(int idx, struct cgroup *cgroup, >> + struct page *page) > > deserves a comment about the locking (needs to be called with > hugetlb_lock). will do > >> +{ >> + int csize; >> + struct res_counter *counter; >> + struct res_counter *fail_res; >> + struct hugetlb_cgroup *page_hcg; >> + struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup); >> + struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(cgroup); >> + >> + if (!get_page_unless_zero(page)) >> + goto out; >> + >> + page_hcg = hugetlb_cgroup_from_page(page); >> + /* >> + * We can have pages in active list without any cgroup >> + * ie, hugepage with less than 3 pages. We can safely >> + * ignore those pages. >> + */ >> + if (!page_hcg || page_hcg != h_cg) >> + goto err_out; > > How can we have page_hcg != NULL && page_hcg != h_cg? pages belonging to other cgroup ? -aneesh