From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id 6AF576B025F for ; Wed, 9 Aug 2017 02:44:42 -0400 (EDT) Received: by mail-pg0-f71.google.com with SMTP id y192so56451538pgd.12 for ; Tue, 08 Aug 2017 23:44:42 -0700 (PDT) Received: from out4440.biz.mail.alibaba.com (out4440.biz.mail.alibaba.com. [47.88.44.40]) by mx.google.com with ESMTP id i72si2121533pfj.386.2017.08.08.23.44.40 for ; Tue, 08 Aug 2017 23:44:41 -0700 (PDT) Date: Wed, 09 Aug 2017 14:44:23 +0800 Subject: memcg Can't context between v1 and v2 because css->refcnt not released From: "=?GBK?B?0/fN+w==?=" Message-ID: Mime-version: 1.0 Content-type: text/plain; charset="US-ASCII" Content-transfer-encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner , Michal Hocko , Tejun Heo , cgroups@vger.kernel.org, linux-mm@kvack.org Hello Johannes ,Michal,and Tejun: i using memcg v1, but some reason i want to context to memcg v2, but i can't, here is my step: #cat /proc/cgroups #subsys_name hierarchy num_cgroups enabled memory 5 1 1 #cd /sys/fs/cgroup/memory #mkdir a #echo 0 > a/cgroup.procs #sleep 1 #echo 0 > cgroup.procs #cat /proc/cgroups #subsys_name hierarchy num_cgroups enabled memory 5 2 1 the num_cgroups not go to "1" so it will lead to can't context to memcg 2 #cd .. #umount memory umount: /sys/fs/cgroup/memory: target is busy. (In some cases useful info about processes that use the device is found by lsof(8) or fuser(1)) and i have tracked the root cause, i found that "b2052564e66d mm: memcontrol: continue cache reclaim from offlined groups"from Johannes Weiner, remove mem_cgroup_reparent_charges when mem_cgroup_css_offline, so the css->refcount not go to "0", so the css_release not call when rmdir cgroup, and nr_cgroups not released. so i want to ask does it reasonable can't context between v1 and v2 -- 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