Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756165Ab2ENLtv (ORCPT ); Mon, 14 May 2012 07:49:51 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:39835 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755595Ab2ENLtu (ORCPT ); Mon, 14 May 2012 07:49:50 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.4.0 Message-ID: <4FB0F174.1000400@jp.fujitsu.com> Date: Mon, 14 May 2012 20:50:12 +0900 From: Yasuaki Ishimatsu User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Lai Jiangshan CC: Mel Gorman , Andrew Morton , linux-mm@kvack.org, LKML Subject: Re: [PATCH] memory: add kernelcore_max_addr boot option References: <4FACA79C.9070103@cn.fujitsu.com> In-Reply-To: <4FACA79C.9070103@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6490 Lines: 162 Hi Lai, Your patch does not consider allocated memory from memblock. Thus even if I set the kernelcore_max_addr boot option, movable node cannot be created. I made sample patches that limited the memory from memblock. [Patch 1/4] x86: get pg_data_t's memory from other node [Patch 2/4] x86: use memblock_set_current_limit() to set memblock.current_limit [Patch 3/4] memblock: limit memory address from memblock [Patch 4/4] memblock: compare current_limit with end variable at memblock_find_in_range_node() System seems to be able to create movable node by applying these patches. But there are two problems. - When online memory of movable zone is under 512MB by offlining memory, system cannot create new process. - When all memory of movable zone is offlined, "kernel BUG at mm/slub.c:3587!" message is shown. I have not understood the root cause of the problems. Thanks, Yasuaki Ishimatsu 2012/05/11 14:46, Lai Jiangshan wrote: > Current ZONE_MOVABLE (kernelcore=) setting policy with boot option doesn't meet > our requirement. We need something like kernelcore_max_addr= boot option > to limit the kernelcore upper address. > > The memory with higher address will be migratable(movable) and they > are easier to be offline(always ready to be offline when the system don't require > so much memory). > > All kernelcore_max_addr=, kernelcore= and movablecore= can be safely specified > at the same time(or any 2 of them). > > Signed-off-by: Lai Jiangshan > --- > Documentation/kernel-parameters.txt | 9 +++++++++ > mm/page_alloc.c | 27 ++++++++++++++++++++++++++- > 2 files changed, 35 insertions(+), 1 deletions(-) > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index c1601e5..9f42787 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -1184,6 +1184,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > use the HighMem zone if it exists, and the Normal > zone if it does not. > > + kernelcore_max_addr=nn[KMG] [KNL,X86,IA-64,PPC] This parameter > + is the same effect as kernelcore parameter, except it > + specifies the up physical address of memory range > + usable by the kernel for non-movable allocations. > + If both kernelcore and kernelcore_max_addr are > + specified, this requested's priority is higher than > + kernelcore's. > + See the kernelcore parameter. > + > kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port. > Format:[,poll interval] > The controller # is the number of the ehci usb debug > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index a712fb9..9169ea9 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -200,6 +200,7 @@ static unsigned long __meminitdata dma_reserve; > #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP > static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; > static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; > +static unsigned long __initdata required_kernelcore_max_pfn; > static unsigned long __initdata required_kernelcore; > static unsigned long __initdata required_movablecore; > static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; > @@ -4568,6 +4569,7 @@ static void __init find_zone_movable_pfns_for_nodes(void) > { > int i, nid; > unsigned long usable_startpfn; > + unsigned long kernelcore_max_pfn; > unsigned long kernelcore_node, kernelcore_remaining; > /* save the state before borrow the nodemask */ > nodemask_t saved_node_state = node_states[N_HIGH_MEMORY]; > @@ -4596,6 +4598,9 @@ static void __init find_zone_movable_pfns_for_nodes(void) > required_kernelcore = max(required_kernelcore, corepages); > } > > + if (required_kernelcore_max_pfn&& !required_kernelcore) > + required_kernelcore = totalpages; > + > /* If kernelcore was not specified, there is no ZONE_MOVABLE */ > if (!required_kernelcore) > goto out; > @@ -4604,6 +4609,12 @@ static void __init find_zone_movable_pfns_for_nodes(void) > find_usable_zone_for_movable(); > usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; > > + if (required_kernelcore_max_pfn) > + kernelcore_max_pfn = required_kernelcore_max_pfn; > + else > + kernelcore_max_pfn = ULONG_MAX>> PAGE_SHIFT; > + kernelcore_max_pfn = max(kernelcore_max_pfn, usable_startpfn); > + > restart: > /* Spread kernelcore memory as evenly as possible throughout nodes */ > kernelcore_node = required_kernelcore / usable_nodes; > @@ -4630,8 +4641,12 @@ restart: > unsigned long size_pages; > > start_pfn = max(start_pfn, zone_movable_pfn[nid]); > - if (start_pfn>= end_pfn) > + end_pfn = min(kernelcore_max_pfn, end_pfn); > + if (start_pfn>= end_pfn) { > + if (!zone_movable_pfn[nid]) > + zone_movable_pfn[nid] = start_pfn; > continue; > + } > > /* Account for what is only usable for kernelcore */ > if (start_pfn< usable_startpfn) { > @@ -4816,6 +4831,15 @@ static int __init cmdline_parse_core(char *p, unsigned long *core) > } > > /* > + * kernelcore_max_addr=addr sets the up physical address of memory range > + * for use for allocations that cannot be reclaimed or migrated. > + */ > +static int __init cmdline_parse_kernelcore_max_addr(char *p) > +{ > + return cmdline_parse_core(p,&required_kernelcore_max_pfn); > +} > + > +/* > * kernelcore=size sets the amount of memory for use for allocations that > * cannot be reclaimed or migrated. > */ > @@ -4833,6 +4857,7 @@ static int __init cmdline_parse_movablecore(char *p) > return cmdline_parse_core(p,&required_movablecore); > } > > +early_param("kernelcore_max_addr", cmdline_parse_kernelcore_max_addr); > early_param("kernelcore", cmdline_parse_kernelcore); > early_param("movablecore", cmdline_parse_movablecore); > > > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. 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