From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 4560F6B0089 for ; Sun, 21 Nov 2010 10:26:06 -0500 (EST) Received: by pwi6 with SMTP id 6so1274853pwi.14 for ; Sun, 21 Nov 2010 07:26:04 -0800 (PST) Date: Mon, 22 Nov 2010 00:25:56 +0900 From: Minchan Kim Subject: Re: [PATCH 3/4] alloc_contig_pages() allocate big chunk memory using migration Message-ID: <20101121152556.GC20947@barrios-desktop> References: <20101119171033.a8d9dc8f.kamezawa.hiroyu@jp.fujitsu.com> <20101119171528.32674ef4.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101119171528.32674ef4.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Bob Liu , fujita.tomonori@lab.ntt.co.jp, m.nazarewicz@samsung.com, pawel@osciak.com, andi.kleen@intel.com, felipe.contreras@gmail.com, "akpm@linux-foundation.org" , "kosaki.motohiro@jp.fujitsu.com" List-ID: On Fri, Nov 19, 2010 at 05:15:28PM +0900, KAMEZAWA Hiroyuki wrote: > From: KAMEZAWA Hiroyuki > > Add an function to allocate contiguous memory larger than MAX_ORDER. > The main difference between usual page allocator is that this uses > memory offline technique (Isolate pages and migrate remaining pages.). > > I think this is not 100% solution because we can't avoid fragmentation, > but we have kernelcore= boot option and can create MOVABLE zone. That > helps us to allow allocate a contiguous range on demand. > > The new function is > > alloc_contig_pages(base, end, nr_pages, alignment) > > This function will allocate contiguous pages of nr_pages from the range > [base, end). If [base, end) is bigger than nr_pages, some pfn which > meats alignment will be allocated. If alignment is smaller than MAX_ORDER, > it will be raised to be MAX_ORDER. > > __alloc_contig_pages() has much more arguments. > > > Some drivers allocates contig pages by bootmem or hiding some memory > from the kernel at boot. But if contig pages are necessary only in some > situation, kernelcore= boot option and using page migration is a choice. > > Changelog: 2010-11-19 > - removed no_search > - removed some drain_ functions because they are heavy. > - check -ENOMEM case > > Changelog: 2010-10-26 > - support gfp_t > - support zonelist/nodemask > - support [base, end) > - support alignment > > Signed-off-by: KAMEZAWA Hiroyuki Acked-by: Minchan Kim Trivial comment below. > +EXPORT_SYMBOL_GPL(alloc_contig_pages); > + > +struct page *alloc_contig_pages_host(unsigned long nr_pages, int align_order) > +{ > + return __alloc_contig_pages(0, max_pfn, nr_pages, align_order, -1, > + GFP_KERNEL | __GFP_MOVABLE, NULL); > +} We need include #include for using max_pfn. -- Kind regards, Minchan Kim -- 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 policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org