From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932112Ab2ILM4v (ORCPT ); Wed, 12 Sep 2012 08:56:51 -0400 Received: from e23smtp05.au.ibm.com ([202.81.31.147]:55028 "EHLO e23smtp05.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758452Ab2ILM4t (ORCPT ); Wed, 12 Sep 2012 08:56:49 -0400 Message-ID: <50508689.50904@linux.vnet.ibm.com> Date: Wed, 12 Sep 2012 20:56:41 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120827 Thunderbird/15.0 MIME-Version: 1.0 To: Xiao Guangrong CC: Andrew Morton , Hugh Dickins , Linux Memory Management List , LKML Subject: [PATCH 2/3] thp: move release mmap_sem lock out of khugepaged_alloc_page References: <50508632.9090003@linux.vnet.ibm.com> In-Reply-To: <50508632.9090003@linux.vnet.ibm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit x-cbid: 12091212-1396-0000-0000-000001DCFDD8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To make the code more clear, move release the lock out of khugepaged_alloc_page Signed-off-by: Xiao Guangrong --- mm/huge_memory.c | 14 +++++++------- 1 files changed, 7 insertions(+), 7 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 66d2bc6..5622347 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1854,11 +1854,6 @@ static struct page *hpage = alloc_hugepage_vma(khugepaged_defrag(), vma, address, node, __GFP_OTHER_NODE); - /* - * After allocating the hugepage, release the mmap_sem read lock in - * preparation for taking it in write mode. - */ - up_read(&mm->mmap_sem); if (unlikely(!*hpage)) { count_vm_event(THP_COLLAPSE_ALLOC_FAILED); *hpage = ERR_PTR(-ENOMEM); @@ -1905,7 +1900,6 @@ static struct page struct vm_area_struct *vma, unsigned long address, int node) { - up_read(&mm->mmap_sem); VM_BUG_ON(!*hpage); return *hpage; } @@ -1931,8 +1925,14 @@ static void collapse_huge_page(struct mm_struct *mm, VM_BUG_ON(address & ~HPAGE_PMD_MASK); - /* release the mmap_sem read lock. */ new_page = khugepaged_alloc_page(hpage, mm, vma, address, node); + + /* + * After allocating the hugepage, release the mmap_sem read lock in + * preparation for taking it in write mode. + */ + up_read(&mm->mmap_sem); + if (!new_page) return; -- 1.7.7.6