From patchwork Wed Jun 15 20:06:37 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A . Shutemov" X-Patchwork-Id: 9179309 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BD489604DB for ; Wed, 15 Jun 2016 20:10:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AA1391FE7B for ; Wed, 15 Jun 2016 20:10:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9EB9D27DCE; Wed, 15 Jun 2016 20:10:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2889D1FE7B for ; Wed, 15 Jun 2016 20:10:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933176AbcFOUJX (ORCPT ); Wed, 15 Jun 2016 16:09:23 -0400 Received: from mga02.intel.com ([134.134.136.20]:54748 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932834AbcFOUH2 (ORCPT ); Wed, 15 Jun 2016 16:07:28 -0400 Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga101.jf.intel.com with ESMTP; 15 Jun 2016 13:07:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,477,1459839600"; d="scan'208";a="828804317" Received: from black.fi.intel.com ([10.237.72.93]) by orsmga003.jf.intel.com with ESMTP; 15 Jun 2016 13:07:00 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 2115BDD1; Wed, 15 Jun 2016 23:06:50 +0300 (EEST) From: "Kirill A. Shutemov" To: Hugh Dickins , Andrea Arcangeli , Andrew Morton Cc: Dave Hansen , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Jerome Marchand , Yang Shi , Sasha Levin , Andres Lagar-Cavilla , Ning Qu , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Ebru Akagunduz , "Kirill A. Shutemov" Subject: [PATCHv9-rebased2 32/37] khugepaged: move up_read(mmap_sem) out of khugepaged_alloc_page() Date: Wed, 15 Jun 2016 23:06:37 +0300 Message-Id: <1466021202-61880-33-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1466021202-61880-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1465222029-45942-1-git-send-email-kirill.shutemov@linux.intel.com> <1466021202-61880-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Both variants of khugepaged_alloc_page() do up_read(&mm->mmap_sem) first: no point keep it inside the function. Signed-off-by: Kirill A. Shutemov --- mm/khugepaged.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 3e6d1a1b7e2c..639047cc6ea7 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -739,19 +739,10 @@ static bool khugepaged_prealloc_page(struct page **hpage, bool *wait) } static struct page * -khugepaged_alloc_page(struct page **hpage, gfp_t gfp, struct mm_struct *mm, - unsigned long address, int node) +khugepaged_alloc_page(struct page **hpage, gfp_t gfp, int node) { VM_BUG_ON_PAGE(*hpage, *hpage); - /* - * Before allocating the hugepage, release the mmap_sem read lock. - * The allocation can take potentially a long time if it involves - * sync compaction, and we do not need to hold the mmap_sem during - * that. We will recheck the vma after taking it again in write mode. - */ - up_read(&mm->mmap_sem); - *hpage = __alloc_pages_node(node, gfp, HPAGE_PMD_ORDER); if (unlikely(!*hpage)) { count_vm_event(THP_COLLAPSE_ALLOC_FAILED); @@ -812,10 +803,8 @@ static bool khugepaged_prealloc_page(struct page **hpage, bool *wait) } static struct page * -khugepaged_alloc_page(struct page **hpage, gfp_t gfp, struct mm_struct *mm, - unsigned long address, int node) +khugepaged_alloc_page(struct page **hpage, gfp_t gfp, int node) { - up_read(&mm->mmap_sem); VM_BUG_ON(!*hpage); return *hpage; @@ -936,8 +925,14 @@ static void collapse_huge_page(struct mm_struct *mm, /* Only allocate from the target node */ gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_OTHER_NODE | __GFP_THISNODE; - /* release the mmap_sem read lock. */ - new_page = khugepaged_alloc_page(hpage, gfp, mm, address, node); + /* + * Before allocating the hugepage, release the mmap_sem read lock. + * The allocation can take potentially a long time if it involves + * sync compaction, and we do not need to hold the mmap_sem during + * that. We will recheck the vma after taking it again in write mode. + */ + up_read(&mm->mmap_sem); + new_page = khugepaged_alloc_page(hpage, gfp, node); if (!new_page) { result = SCAN_ALLOC_HUGE_PAGE_FAIL; goto out_nolock;