From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 3329F6B00FB for ; Fri, 6 Mar 2009 04:23:41 -0500 (EST) Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by e28smtp02.in.ibm.com (8.13.1/8.13.1) with ESMTP id n269NYH1032503 for ; Fri, 6 Mar 2009 14:53:34 +0530 Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n269KV8w4329626 for ; Fri, 6 Mar 2009 14:50:31 +0530 Received: from d28av03.in.ibm.com (loopback [127.0.0.1]) by d28av03.in.ibm.com (8.13.1/8.13.3) with ESMTP id n269NXng032226 for ; Fri, 6 Mar 2009 20:23:34 +1100 From: Balbir Singh Date: Fri, 06 Mar 2009 14:53:30 +0530 Message-Id: <20090306092330.21063.2864.sendpatchset@localhost.localdomain> In-Reply-To: <20090306092323.21063.93169.sendpatchset@localhost.localdomain> References: <20090306092323.21063.93169.sendpatchset@localhost.localdomain> Subject: [PATCH 1/4] Memory controller soft limit documentation (v4) Sender: owner-linux-mm@kvack.org To: linux-mm@kvack.org Cc: Sudhir Kumar , YAMAMOTO Takashi , Bharata B Rao , Paul Menage , lizf@cn.fujitsu.com, linux-kernel@vger.kernel.org, KOSAKI Motohiro , David Rientjes , Pavel Emelianov , Dhaval Giani , Balbir Singh , Rik van Riel , Andrew Morton , KAMEZAWA Hiroyuki List-ID: Feature: Add documentation for soft limits From: Balbir Singh Signed-off-by: Balbir Singh --- Documentation/cgroups/memory.txt | 27 ++++++++++++++++++++++++++- 1 files changed, 26 insertions(+), 1 deletions(-) diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index a98a7fe..812cb74 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -360,7 +360,32 @@ cgroups created below it. NOTE2: This feature can be enabled/disabled per subtree. -7. TODO +7. Soft limits + +Soft limits allow for greater sharing of memory. The idea behind soft limits +is to allow control groups to use as much of the memory as needed, provided + +a. There is no memory contention +b. They do not exceed their hard limit + +When the system detects memory contention or low memory (kswapd is woken up) +control groups are pushed back to their soft limits. If the soft limit of each +control group is very high, they are pushed back as much as possible to make +sure that one control group does not starve the others of memory. + +7.1 Interface + +Soft limits can be setup by using the following commands (in this example we +assume a soft limit of 256 megabytes) + +# echo 256M > memory.soft_limit_in_bytes + +If we want to change this to 1G, we can at any time use + +# echo 1G > memory.soft_limit_in_bytes + + +8. TODO 1. Add support for accounting huge pages (as a separate controller) 2. Make per-cgroup scanner reclaim not-shared pages first -- Balbir -- 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