Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755059AbYCQBfT (ORCPT ); Sun, 16 Mar 2008 21:35:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752864AbYCQBfH (ORCPT ); Sun, 16 Mar 2008 21:35:07 -0400 Received: from E23SMTP01.au.ibm.com ([202.81.18.162]:42371 "EHLO e23smtp01.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752486AbYCQBfF (ORCPT ); Sun, 16 Mar 2008 21:35:05 -0400 Message-ID: <47DDCA6B.7090207@linux.vnet.ibm.com> Date: Mon, 17 Mar 2008 07:03:31 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com Organization: IBM User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: Randy Dunlap CC: linux-mm@kvack.org, Hugh Dickins , Sudhir Kumar , YAMAMOTO Takashi , Paul Menage , lizf@cn.fujitsu.com, linux-kernel@vger.kernel.org, taka@valinux.co.jp, David Rientjes , Pavel Emelianov , Andrew Morton , KAMEZAWA Hiroyuki Subject: Re: [RFC][3/3] Update documentation for virtual address space control References: <20080316172942.8812.56051.sendpatchset@localhost.localdomain> <20080316173017.8812.41614.sendpatchset@localhost.localdomain> <20080316113200.cc6da618.randy.dunlap@oracle.com> In-Reply-To: <20080316113200.cc6da618.randy.dunlap@oracle.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3158 Lines: 91 Randy Dunlap wrote: > On Sun, 16 Mar 2008 23:00:17 +0530 Balbir Singh wrote: > >> This patch adds documentation for virtual address space control. >> >> Signed-off-by: Balbir Singh >> --- >> >> Documentation/controllers/memory.txt | 26 +++++++++++++++++++++++++- >> 1 file changed, 25 insertions(+), 1 deletion(-) >> >> diff -puN Documentation/controllers/memory.txt~memory-controller-virtual-address-control-documentation Documentation/controllers/memory.txt >> --- linux-2.6.25-rc5/Documentation/controllers/memory.txt~memory-controller-virtual-address-control-documentation 2008-03-16 22:57:44.000000000 +0530 >> +++ linux-2.6.25-rc5-balbir/Documentation/controllers/memory.txt 2008-03-16 22:57:44.000000000 +0530 >> @@ -237,7 +237,31 @@ cgroup might have some charge associated >> tasks have migrated away from it. Such charges are automatically dropped at >> rmdir() if there are no tasks. >> >> -5. TODO >> +5. Virtual address space accounting >> + >> +A new resource counter controls the address space expansion of the tasks in >> +the cgroup. Address space control is provided along the same lines as >> +RLIMIT_AS control, which is available via getrlimit(2)/setrlimit(2). >> +The interface for controlling address space is provided through >> +"as_limit_in_bytes". The file is similar to "limit_in_bytes" w.r.t the user > > w.r.t. > or even spelled out. > Will spell out. >> +interface. Please see section 3 for more details on how to use the user >> +interface to get and set values. >> + >> +The "as_usage_in_bytes" file provides information about the total address >> +space usage of the cgroup in bytes. >> + >> +5.1 Advantages of providing this feature >> + >> +1. Control over virtual address space allows for a cgroup to fail gracefully >> + i.e, via a malloc or mmap failure as compared to OOM kill when no > > i.e., > >> + pages can be reclaimed > > end with period. Will fix > >> +2. It provides better control over how many pages can be swapped out when >> + the cgroup goes over it's limit. A badly setup cgroup can cause excessive > > its (not "it is") > Will fix :) >> + swapping. Providing control over the address space allocations ensures >> + that the system administrator has control over the total swapping that >> + can take place. >> + >> +6. TODO >> >> 1. Add support for accounting huge pages (as a separate controller) >> 2. Make per-cgroup scanner reclaim not-shared pages first >> _ > > --- > ~Randy > > -- > 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 -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/