From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kamezawa Hiroyuki Subject: Re: [PATCH -V8 12/16] hugetlb/cgroup: Add support for cgroup removal Date: Tue, 12 Jun 2012 17:23:18 +0900 Message-ID: <4FD6FC76.8040203@jp.fujitsu.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> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1339232401-14392-13-git-send-email-aneesh.kumar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: "Aneesh Kumar K.V" Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, dhillf-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, rientjes-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, mhocko-AlSwsSmVLrQ@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 (2012/06/09 17:59), 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 I'm sorry if already pointed out.... > --- > 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) > +{ > + 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; It seems this doesn't necessary...this is under hugetlb_lock(). > + > + 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; > + > + csize = PAGE_SIZE<< compound_order(page); > + if (!parent) { > + parent = root_h_cgroup; > + /* root has no limit */ > + res_counter_charge_nofail(&parent->hugepage[idx], > + csize,&fail_res); ^^^ space ? > + } > + counter =&h_cg->hugepage[idx]; > + res_counter_uncharge_until(counter, counter->parent, csize); > + > + set_hugetlb_cgroup(page, parent); > +err_out: > + put_page(page); > +out: > + return 0; > +} > + > +/* > + * Force the hugetlb cgroup to empty the hugetlb resources by moving them to > + * the parent cgroup. > + */ > static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup) > { > - /* We will add the cgroup removal support in later patches */ > - return -EBUSY; > + struct hstate *h; > + struct page *page; > + int ret = 0, idx = 0; > + > + do { > + if (cgroup_task_count(cgroup) || > + !list_empty(&cgroup->children)) { > + ret = -EBUSY; > + goto out; > + } > + /* > + * If the task doing the cgroup_rmdir got a signal > + * we don't really need to loop till the hugetlb resource > + * usage become zero. > + */ > + if (signal_pending(current)) { > + ret = -EINTR; > + goto out; > + } I'll post a patch to remove this check from memcg because memcg's rmdir always succeed now. So, could you remove this ? > + for_each_hstate(h) { > + spin_lock(&hugetlb_lock); > + list_for_each_entry(page,&h->hugepage_activelist, lru) { > + ret = hugetlb_cgroup_move_parent(idx, cgroup, page); > + if (ret) { When 'ret' should be !0 ? If hugetlb_cgroup_move_parent() always returns 0, the check will not be necessary. Thanks, -Kame > + spin_unlock(&hugetlb_lock); > + goto out; > + } > + } > + spin_unlock(&hugetlb_lock); > + idx++; > + } > + cond_resched(); > + } while (hugetlb_cgroup_have_usage(cgroup)); > +out: > + return ret; > } > > int hugetlb_cgroup_charge_page(int idx, unsigned long nr_pages,