From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 9BE888D0080 for ; Wed, 17 Nov 2010 03:16:51 -0500 (EST) Received: from hpaq11.eem.corp.google.com (hpaq11.eem.corp.google.com [172.25.149.11]) by smtp-out.google.com with ESMTP id oAH8GjIM020230 for ; Wed, 17 Nov 2010 00:16:45 -0800 Received: from gwj17 (gwj17.prod.google.com [10.200.10.17]) by hpaq11.eem.corp.google.com with ESMTP id oAH8GfSC030470 for ; Wed, 17 Nov 2010 00:16:43 -0800 Received: by gwj17 with SMTP id 17so946245gwj.19 for ; Wed, 17 Nov 2010 00:16:40 -0800 (PST) Date: Wed, 17 Nov 2010 00:16:34 -0800 (PST) From: David Rientjes Subject: Re: [1/8,v3] NUMA Hotplug Emulator: add function to hide memory region via e820 table. In-Reply-To: <20101117021000.479272928@intel.com> Message-ID: References: <20101117020759.016741414@intel.com> <20101117021000.479272928@intel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Shaohui Zheng Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, haicheng.li@linux.intel.com, lethal@linux-sh.org, ak@linux.intel.com, shaohui.zheng@linux.intel.com, Yinghai Lu , Haicheng Li List-ID: On Wed, 17 Nov 2010, shaohui.zheng@intel.com wrote: > Index: linux-hpe4/arch/x86/kernel/e820.c > =================================================================== > --- linux-hpe4.orig/arch/x86/kernel/e820.c 2010-11-15 17:13:02.483461667 +0800 > +++ linux-hpe4/arch/x86/kernel/e820.c 2010-11-15 17:13:07.083461581 +0800 > @@ -971,6 +971,7 @@ > } > > static int userdef __initdata; > +static u64 max_mem_size __initdata = ULLONG_MAX; > > /* "mem=nopentium" disables the 4MB page tables. */ > static int __init parse_memopt(char *p) > @@ -989,12 +990,28 @@ > > userdef = 1; > mem_size = memparse(p, &p); > - e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1); > + e820_remove_range(mem_size, max_mem_size - mem_size, E820_RAM, 1); > + max_mem_size = mem_size; > > return 0; > } This needs memmap= support as well, right? > early_param("mem", parse_memopt); > > +#ifdef CONFIG_NODE_HOTPLUG_EMU > +u64 __init e820_hide_mem(u64 mem_size) > +{ > + u64 start, end_pfn; > + > + userdef = 1; > + end_pfn = e820_end_of_ram_pfn(); > + start = (end_pfn << PAGE_SHIFT) - mem_size; > + e820_remove_range(start, max_mem_size - start, E820_RAM, 1); > + max_mem_size = start; > + > + return start; > +} > +#endif This doesn't have any sanity checking for whether e820_remove_range() will leave any significant amount of memory behind so the kernel will even boot (probably should have a guaranteed FAKE_NODE_MIN_SIZE left behind?). > + > static int __init parse_memmap_opt(char *p) > { > char *oldp; -- 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