Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755770Ab0KOIfr (ORCPT ); Mon, 15 Nov 2010 03:35:47 -0500 Received: from cantor2.suse.de ([195.135.220.15]:52057 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751447Ab0KOIfq (ORCPT ); Mon, 15 Nov 2010 03:35:46 -0500 Date: Mon, 15 Nov 2010 09:35:40 +0100 From: Michal Hocko To: Daisuke Nishimura Cc: linux-mm@kvack.org, KAMEZAWA Hiroyuki , linux-kernel@vger.kernel.org, Andrew Morton , balbir@linux.vnet.ibm.com Subject: Re: [RFC PATCH] Make swap accounting default behavior configurable v3 Message-ID: <20101115083540.GA20156@tiehlicka.suse.cz> References: <20101110125154.GC5867@tiehlicka.suse.cz> <20101111094613.eab2ec0b.nishimura@mxp.nes.nec.co.jp> <20101111093155.GA20630@tiehlicka.suse.cz> <20101112094118.b02b669f.nishimura@mxp.nes.nec.co.jp> <20101112083103.GB7285@tiehlicka.suse.cz> <20101115101335.8880fd87.nishimura@mxp.nes.nec.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101115101335.8880fd87.nishimura@mxp.nes.nec.co.jp> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6175 Lines: 163 On Mon 15-11-10 10:13:35, Daisuke Nishimura wrote: > On Fri, 12 Nov 2010 09:31:03 +0100 [...] > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > > index ed45e98..7077148 100644 > > --- a/Documentation/kernel-parameters.txt > > +++ b/Documentation/kernel-parameters.txt > > @@ -1752,6 +1752,8 @@ and is between 256 and 4096 characters. It is defined in the file > > > > noswapaccount [KNL] Disable accounting of swap in memory resource > > controller. (See Documentation/cgroups/memory.txt) > > + swapaccount [KNL] Enable accounting of swap in memory resource > > + controller. (See Documentation/cgroups/memory.txt) > > > > nosync [HW,M68K] Disables sync negotiation for all devices. > > > (I've add Andrew and Balbir to CC-list.) > It seems that almost all parameters are listed in alphabetic order in the document, > so I think it would be better to obey the rule. You are right. The header of the file says: " The following is a consolidated list of the kernel parameters as implemented (mostly) by the __setup() macro and sorted into English Dictionary order (defined as ignoring all punctuation and sorting digits before letters in a case insensitive manner), and with descriptions where known." Updated patch follows bellow. > > Thanks, > Daisuke Nishimura. Changes since v2: * put the new parameter description to the proper (alphabetically sorted) place in Documentation/kernel-parameters.txt Changes since v1: * do not remove noswapaccount parameter and add swapaccount parameter instead * Documentation/kernel-parameters.txt updated --- >From 21df3801e2b65f47a2807534487ebb353dad6340 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Wed, 10 Nov 2010 13:30:04 +0100 Subject: [PATCH] Make swap accounting default behavior configurable Swap accounting can be configured by CONFIG_CGROUP_MEM_RES_CTLR_SWAP configuration option and then it is turned on by default. There is a boot option (noswapaccount) which can disable this feature. This makes it hard for distributors to enable the configuration option as this feature leads to a bigger memory consumption and this is a no-go for general purpose distribution kernel. On the other hand swap accounting may be very usuful for some workloads. This patch adds a new configuration option which controls the default behavior (CGROUP_MEM_RES_CTLR_SWAP_ENABLED). If the option is selected then the feature is turned on by default. It also adds a new boot parameter swapaccount which (contrary to noswapaccount) enables the feature. (I would consider swapaccount=yes|no semantic with removed noswapaccount parameter much better but this parameter is kind of API which might be in use and unexpected breakage is no-go.) The default behavior is unchanged (if CONFIG_CGROUP_MEM_RES_CTLR_SWAP is enabled then CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED is enabled as well) Signed-off-by: Michal Hocko --- Documentation/kernel-parameters.txt | 3 +++ init/Kconfig | 13 +++++++++++++ mm/memcontrol.c | 15 ++++++++++++++- 3 files changed, 30 insertions(+), 1 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index ed45e98..14eafa5 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2385,6 +2385,9 @@ and is between 256 and 4096 characters. It is defined in the file improve throughput, but will also increase the amount of memory reserved for use by the client. + swapaccount [KNL] Enable accounting of swap in memory resource + controller. (See Documentation/cgroups/memory.txt) + swiotlb= [IA-64] Number of I/O TLB slabs switches= [HW,M68k] diff --git a/init/Kconfig b/init/Kconfig index 88c1046..c972899 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -613,6 +613,19 @@ config CGROUP_MEM_RES_CTLR_SWAP if boot option "noswapaccount" is set, swap will not be accounted. Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page size is 4096bytes, 512k per 1Gbytes of swap. +config CGROUP_MEM_RES_CTLR_SWAP_ENABLED + bool "Memory Resource Controller Swap Extension enabled by default" + depends on CGROUP_MEM_RES_CTLR_SWAP + default y + help + Memory Resource Controller Swap Extension comes with its price in + a bigger memory consumption. General purpose distribution kernels + which want to enable the feautre but keep it disabled by default + and let the user enable it by swapaccount boot command line + parameter should have this option unselected. + For those who want to have the feature enabled by default should + select this option (if, for some reason, they need to disable it + then noswapaccount does the trick). menuconfig CGROUP_SCHED bool "Group CPU scheduler" diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 9a99cfa..4f479fe 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -61,7 +61,14 @@ struct mem_cgroup *root_mem_cgroup __read_mostly; #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ int do_swap_account __read_mostly; -static int really_do_swap_account __initdata = 1; /* for remember boot option*/ + +/* for remember boot option*/ +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED +static int really_do_swap_account __initdata = 1; +#else +static int really_do_swap_account __initdata = 0; +#endif + #else #define do_swap_account (0) #endif @@ -4909,6 +4916,12 @@ struct cgroup_subsys mem_cgroup_subsys = { }; #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP +static int __init enable_swap_account(char *s) +{ + really_do_swap_account = 1; + return 1; +} +__setup("swapaccount", enable_swap_account); static int __init disable_swap_account(char *s) { -- 1.7.2.3 -- Michal Hocko L3 team SUSE LINUX s.r.o. 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