Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964928Ab2KVS6l (ORCPT ); Thu, 22 Nov 2012 13:58:41 -0500 Received: from terminus.zytor.com ([198.137.202.10]:37038 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964892Ab2KVS6h (ORCPT ); Thu, 22 Nov 2012 13:58:37 -0500 Date: Wed, 21 Nov 2012 17:57:11 -0800 From: tip-bot for Yinghai Lu Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, yinghai@kernel.org, tglx@linutronix.de, hpa@linux.intel.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, yinghai@kernel.org, tglx@linutronix.de, hpa@linux.intel.com In-Reply-To: <1353123563-3103-20-git-send-email-yinghai@kernel.org> References: <1353123563-3103-20-git-send-email-yinghai@kernel.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/mm2] x86, mm: Don't clear page table if range is ram Git-Commit-ID: eceb3632ac85bc08fc27f7fc9ab85672681b2635 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (terminus.zytor.com [127.0.0.1]); Wed, 21 Nov 2012 17:57:16 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3906 Lines: 115 Commit-ID: eceb3632ac85bc08fc27f7fc9ab85672681b2635 Gitweb: http://git.kernel.org/tip/eceb3632ac85bc08fc27f7fc9ab85672681b2635 Author: Yinghai Lu AuthorDate: Fri, 16 Nov 2012 19:38:56 -0800 Committer: H. Peter Anvin CommitDate: Sat, 17 Nov 2012 11:59:17 -0800 x86, mm: Don't clear page table if range is ram After we add code use buffer in BRK to pre-map buf for page table in following patch: x86, mm: setup page table in top-down it should be safe to remove early_memmap for page table accessing. Instead we get panic with that. It turns out that we clear the initial page table wrongly for next range that is separated by holes. And it only happens when we are trying to map ram range one by one. We need to check if the range is ram before clearing page table. We change the loop structure to remove the extra little loop and use one loop only, and in that loop will caculate next at first, and check if [addr,next) is covered by E820_RAM. -v2: E820_RESERVED_KERN is treated as E820_RAM. EFI one change some E820_RAM to that, so next kernel by kexec will know that range is used already. Signed-off-by: Yinghai Lu Link: http://lkml.kernel.org/r/1353123563-3103-20-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin --- arch/x86/mm/init_64.c | 40 +++++++++++++++++++--------------------- 1 file changed, 19 insertions(+), 21 deletions(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 869372a..fa28e3e 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -363,20 +363,20 @@ static unsigned long __meminit phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, pgprot_t prot) { - unsigned pages = 0; + unsigned long pages = 0, next; unsigned long last_map_addr = end; int i; pte_t *pte = pte_page + pte_index(addr); - for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { - + for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) { + next = (addr & PAGE_MASK) + PAGE_SIZE; if (addr >= end) { - if (!after_bootmem) { - for(; i < PTRS_PER_PTE; i++, pte++) - set_pte(pte, __pte(0)); - } - break; + if (!after_bootmem && + !e820_any_mapped(addr & PAGE_MASK, next, E820_RAM) && + !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN)) + set_pte(pte, __pte(0)); + continue; } /* @@ -419,16 +419,15 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, pte_t *pte; pgprot_t new_prot = prot; + next = (address & PMD_MASK) + PMD_SIZE; if (address >= end) { - if (!after_bootmem) { - for (; i < PTRS_PER_PMD; i++, pmd++) - set_pmd(pmd, __pmd(0)); - } - break; + if (!after_bootmem && + !e820_any_mapped(address & PMD_MASK, next, E820_RAM) && + !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN)) + set_pmd(pmd, __pmd(0)); + continue; } - next = (address & PMD_MASK) + PMD_SIZE; - if (pmd_val(*pmd)) { if (!pmd_large(*pmd)) { spin_lock(&init_mm.page_table_lock); @@ -497,13 +496,12 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, pmd_t *pmd; pgprot_t prot = PAGE_KERNEL; - if (addr >= end) - break; - next = (addr & PUD_MASK) + PUD_SIZE; - - if (!after_bootmem && !e820_any_mapped(addr, next, 0)) { - set_pud(pud, __pud(0)); + if (addr >= end) { + if (!after_bootmem && + !e820_any_mapped(addr & PUD_MASK, next, E820_RAM) && + !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN)) + set_pud(pud, __pud(0)); continue; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/