From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx181.postini.com [74.125.245.181]) by kanga.kvack.org (Postfix) with SMTP id 3B58D6B004D for ; Tue, 12 Jun 2012 04:10:30 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 47C753EE0B5 for ; Tue, 12 Jun 2012 17:10:28 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 0386545DE5A for ; Tue, 12 Jun 2012 17:10:28 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id DCC9845DE56 for ; Tue, 12 Jun 2012 17:10:27 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 9A0781DB8053 for ; Tue, 12 Jun 2012 17:10:27 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.240.81.133]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 4FB251DB804E for ; Tue, 12 Jun 2012 17:10:27 +0900 (JST) Message-ID: <4FD6F8F9.2040901@jp.fujitsu.com> Date: Tue, 12 Jun 2012 17:08:25 +0900 From: Kamezawa Hiroyuki MIME-Version: 1.0 Subject: Re: [PATCH -V8 11/16] hugetlb/cgroup: Add charge/uncharge routines for hugetlb cgroup References: <1339232401-14392-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1339232401-14392-12-git-send-email-aneesh.kumar@linux.vnet.ibm.com> In-Reply-To: <1339232401-14392-12-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Aneesh Kumar K.V" Cc: linux-mm@kvack.org, dhillf@gmail.com, rientjes@google.com, mhocko@suse.cz, akpm@linux-foundation.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org (2012/06/09 17:59), Aneesh Kumar K.V wrote: > From: "Aneesh Kumar K.V" > > This patchset add the charge and uncharge routines for hugetlb cgroup. > This will be used in later patches when we allocate/free HugeTLB > pages. > > Signed-off-by: Aneesh Kumar K.V I'm sorry if following has been already pointed out. > --- > mm/hugetlb_cgroup.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 87 insertions(+) > > diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c > index 20a32c5..48efd5a 100644 > --- a/mm/hugetlb_cgroup.c > +++ b/mm/hugetlb_cgroup.c > @@ -105,6 +105,93 @@ static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup) > return -EBUSY; > } > > +int hugetlb_cgroup_charge_page(int idx, unsigned long nr_pages, > + struct hugetlb_cgroup **ptr) > +{ > + int ret = 0; > + struct res_counter *fail_res; > + struct hugetlb_cgroup *h_cg = NULL; > + unsigned long csize = nr_pages * PAGE_SIZE; > + > + if (hugetlb_cgroup_disabled()) > + goto done; > + /* > + * We don't charge any cgroup if the compound page have less > + * than 3 pages. > + */ > + if (hstates[idx].order< 2) > + goto done; > +again: > + rcu_read_lock(); > + h_cg = hugetlb_cgroup_from_task(current); > + if (!h_cg) > + h_cg = root_h_cgroup; > + > + if (!css_tryget(&h_cg->css)) { > + rcu_read_unlock(); > + goto again; > + } > + rcu_read_unlock(); > + > + ret = res_counter_charge(&h_cg->hugepage[idx], csize,&fail_res); > + css_put(&h_cg->css); > +done: > + *ptr = h_cg; > + return ret; > +} > + Memory cgroup uses very complicated 'charge' routine for handling pageout... which gets sleep. For hugetlbfs, it has not sleep routine, you can do charge in simple way. I guess...get/put here is overkill. For example, h_cg cannot be freed while it has tasks. So, if 'current' is belongs to the cgroup, it cannot be disappear. Then, you don't need get/put, additional atomic ops for holding cgroup. rcu_read_lock(); h_cg = hugetlb_cgroup_from_task(current); ret = res_counter_charge(&h_cg->hugetpage[idx], csize, &fail_res); rcu_read_unlock(); return ret; Thanks, -Kame -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org