From patchwork Fri Jul 20 07:14:01 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Congyang X-Patchwork-Id: 1219951 Return-Path: X-Original-To: patchwork-linux-acpi@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id C4A133FD48 for ; Fri, 20 Jul 2012 07:09:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752479Ab2GTHJU (ORCPT ); Fri, 20 Jul 2012 03:09:20 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:10994 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751353Ab2GTHJT (ORCPT ); Fri, 20 Jul 2012 03:09:19 -0400 X-IronPort-AV: E=Sophos;i="4.77,621,1336320000"; d="scan'208";a="5444912" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 20 Jul 2012 15:08:24 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id q6K79BPA031238; Fri, 20 Jul 2012 15:09:13 +0800 Received: from [10.167.225.226] ([10.167.225.226]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2012072015094996-790573 ; Fri, 20 Jul 2012 15:09:49 +0800 Message-ID: <50090539.7020607@cn.fujitsu.com> Date: Fri, 20 Jul 2012 15:14:01 +0800 From: Wen Congyang User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100413 Fedora/3.0.4-2.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org CC: rientjes@google.com, liuj97@gmail.com, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, cl@linux.com, minchan.kim@gmail.com, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com, Yasuaki ISIMATU Subject: [RFC PATCH 8/8] memory-hotplug: implement arch_remove_memory() References: <5009038A.4090001@cn.fujitsu.com> In-Reply-To: <5009038A.4090001@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/07/20 15:09:49, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/07/20 15:09:58, Serialize complete at 2012/07/20 15:09:58 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Set the entry for the removed memory to 0. If the entry related meory is not whole removed, split it to smaller page, and clear it. CC: David Rientjes CC: Jiang Liu CC: Len Brown CC: Benjamin Herrenschmidt CC: Paul Mackerras CC: Christoph Lameter Cc: Minchan Kim CC: Andrew Morton CC: KOSAKI Motohiro CC: Yasuaki Ishimatsu Signed-off-by: Wen Congyang --- arch/x86/mm/init_64.c | 159 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 156 insertions(+), 3 deletions(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 78b94bc..d78f352 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -675,11 +675,164 @@ int arch_add_memory(int nid, u64 start, u64 size) } EXPORT_SYMBOL_GPL(arch_add_memory); +static void __meminit +phys_pte_remove(pte_t *pte_page, unsigned long addr, unsigned long end) +{ + unsigned pages = 0; + int i = pte_index(addr); + + pte_t *pte = pte_page + pte_index(addr); + + for (; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { + + if (addr >= end) + break; + + if (!pte_present(*pte)) + continue; + + pages++; + set_pte(pte, __pte(0)); + } + + update_page_count(PG_LEVEL_4K, -pages); +} + +static void __meminit +phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) +{ + unsigned long pages = 0, next; + int i = pmd_index(addr); + + for (; i < PTRS_PER_PMD; i++, addr = next) { + unsigned long pte_phys; + pmd_t *pmd = pmd_page + pmd_index(addr); + pte_t *pte; + + if (addr >= end) + break; + + next = (addr & PMD_MASK) + PMD_SIZE; + + if (!pmd_present(*pmd)) + continue; + + if (pmd_large(*pmd)) { + if ((addr & ~PMD_MASK) == 0 && next <= end) { + set_pmd(pmd, __pmd(0)); + pages++; + continue; + } + + /* + * We use 2M page, but we need to remove part of them, + * so split 2M page to 4K page. + */ + pte = alloc_low_page(&pte_phys); + __split_large_page((pte_t *)pmd, addr, pte); + + spin_lock(&init_mm.page_table_lock); + pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); + spin_unlock(&init_mm.page_table_lock); + } + + spin_lock(&init_mm.page_table_lock); + pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd)); + phys_pte_remove(pte, addr, end); + unmap_low_page(pte); + spin_unlock(&init_mm.page_table_lock); + } + update_page_count(PG_LEVEL_2M, -pages); +} + +static void __meminit +phys_pud_remove(pud_t *pud_page, unsigned long addr, unsigned long end) +{ + unsigned long pages = 0, next; + int i = pud_index(addr); + + for (; i < PTRS_PER_PUD; i++, addr = next) { + unsigned long pmd_phys; + pud_t *pud = pud_page + pud_index(addr); + pmd_t *pmd; + + if (addr >= end) + break; + + next = (addr & PUD_MASK) + PUD_SIZE; + + if (!pud_present(*pud)) + continue; + + if (pud_large(*pud)) { + if ((addr & ~PUD_MASK) == 0 && next <= end) { + set_pud(pud, __pud(0)); + pages++; + continue; + } + + /* + * We use 1G page, but we need to remove part of them, + * so split 1G page to 2M page. + */ + pmd = alloc_low_page(&pmd_phys); + __split_large_page((pte_t *)pud, addr, (pte_t *)pmd); + + spin_lock(&init_mm.page_table_lock); + pud_populate(&init_mm, pud, __va(pmd_phys)); + spin_unlock(&init_mm.page_table_lock); + } + + pmd = map_low_page(pmd_offset(pud, 0)); + phys_pmd_remove(pmd, addr, end); + unmap_low_page(pmd); + __flush_tlb_all(); + } + __flush_tlb_all(); + + update_page_count(PG_LEVEL_1G, -pages); +} + +void __meminit +kernel_physical_mapping_remove(unsigned long start, unsigned long end) +{ + unsigned long next; + + start = (unsigned long)__va(start); + end = (unsigned long)__va(end); + + for (; start < end; start = next) { + pgd_t *pgd = pgd_offset_k(start); + pud_t *pud; + + next = (start + PGDIR_SIZE) & PGDIR_MASK; + if (next > end) + next = end; + + if (!pgd_present(*pgd)) + continue; + + pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); + phys_pud_remove(pud, __pa(start), __pa(end)); + unmap_low_page(pud); + } + + __flush_tlb_all(); +} + #ifdef CONFIG_MEMORY_HOTREMOVE -int arch_remove_memory(unsigned long start, unsigned long size) +int __ref arch_remove_memory(unsigned long start, unsigned long size) { - /* TODO */ - return -EBUSY; + unsigned long start_pfn = start >> PAGE_SHIFT; + unsigned long nr_pages = size >> PAGE_SHIFT; + int ret; + + ret = __remove_pages(start_pfn, nr_pages); + WARN_ON_ONCE(ret); + + kernel_physical_mapping_remove(start, start + size); + + return ret; } #endif #endif /* CONFIG_MEMORY_HOTPLUG */