From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx164.postini.com [74.125.245.164]) by kanga.kvack.org (Postfix) with SMTP id 95ED16B010A for ; Wed, 28 Mar 2012 10:37:01 -0400 (EDT) Date: Wed, 28 Mar 2012 16:36:58 +0200 From: Michal Hocko Subject: Re: [PATCH -V4 10/10] memcg: Add memory controller documentation for hugetlb management Message-ID: <20120328143658.GJ20949@tiehlicka.suse.cz> References: <1331919570-2264-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1331919570-2264-11-git-send-email-aneesh.kumar@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1331919570-2264-11-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Aneesh Kumar K.V" Cc: linux-mm@kvack.org, mgorman@suse.de, kamezawa.hiroyu@jp.fujitsu.com, dhillf@gmail.com, aarcange@redhat.com, akpm@linux-foundation.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org On Fri 16-03-12 23:09:30, Aneesh Kumar K.V wrote: > From: "Aneesh Kumar K.V" > > Signed-off-by: Aneesh Kumar K.V > --- > Documentation/cgroups/memory.txt | 29 +++++++++++++++++++++++++++++ > 1 files changed, 29 insertions(+), 0 deletions(-) > > diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt > index 4c95c00..d99c41b 100644 > --- a/Documentation/cgroups/memory.txt > +++ b/Documentation/cgroups/memory.txt > @@ -43,6 +43,7 @@ Features: > - usage threshold notifier > - oom-killer disable knob and oom-notifier > - Root cgroup has no limit controls. > + - resource accounting for HugeTLB pages > > Kernel memory support is work in progress, and the current version provides > basically functionality. (See Section 2.7) > @@ -75,6 +76,12 @@ Brief summary of control files. > memory.kmem.tcp.limit_in_bytes # set/show hard limit for tcp buf memory > memory.kmem.tcp.usage_in_bytes # show current tcp buf memory allocation > > + > + memory.hugetlb..limit_in_bytes # set/show limit of "hugepagesize" hugetlb usage > + memory.hugetlb..max_usage_in_bytes # show max "hugepagesize" hugetlb usage recorded > + memory.hugetlb..usage_in_bytes # show current res_counter usage for "hugepagesize" hugetlb > + # see 5.7 for details > + > 1. History > > The memory controller has a long history. A request for comments for the memory > @@ -279,6 +286,15 @@ per cgroup, instead of globally. > > * tcp memory pressure: sockets memory pressure for the tcp protocol. > > +2.8 HugeTLB extension > + > +This extension allows to limit the HugeTLB usage per control group and > +enforces the controller limit during page fault. Since HugeTLB doesn't > +support page reclaim, enforcing the limit at page fault time implies that, > +the application will get SIGBUS signal if it tries to access HugeTLB pages > +beyond its limit. This is consistent with the quota so we should mention that. We should also add a note how we interact with quotas. Another important thing to note is that the limit/usage are unrelated to memcg hard/soft limit/usage. > This requires the application to know beforehand how much > +HugeTLB pages it would require for its use. > + > 3. User Interface > > 0. Configuration > @@ -287,6 +303,7 @@ a. Enable CONFIG_CGROUPS > b. Enable CONFIG_RESOURCE_COUNTERS > c. Enable CONFIG_CGROUP_MEM_RES_CTLR > d. Enable CONFIG_CGROUP_MEM_RES_CTLR_SWAP (to use swap extension) > +f. Enable CONFIG_MEM_RES_CTLR_HUGETLB (to use HugeTLB extension) > > 1. Prepare the cgroups (see cgroups.txt, Why are cgroups needed?) > # mount -t tmpfs none /sys/fs/cgroup > @@ -510,6 +527,18 @@ unevictable= N0= N1= ... > > And we have total = file + anon + unevictable. > > +5.7 HugeTLB resource control files > +For a system supporting two hugepage size (16M and 16G) the control > +files include: > + > + memory.hugetlb.16GB.limit_in_bytes > + memory.hugetlb.16GB.max_usage_in_bytes > + memory.hugetlb.16GB.usage_in_bytes > + memory.hugetlb.16MB.limit_in_bytes > + memory.hugetlb.16MB.max_usage_in_bytes > + memory.hugetlb.16MB.usage_in_bytes > + > + > 6. Hierarchy support > > The memory controller supports a deep hierarchy and hierarchical accounting. > -- > 1.7.9 > -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org