From patchwork Fri Jan 17 23:22:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Yang X-Patchwork-Id: 11339989 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5FF0392A for ; Fri, 17 Jan 2020 23:23:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3791B22464 for ; Fri, 17 Jan 2020 23:23:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3791B22464 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2E4A46B0504; Fri, 17 Jan 2020 18:23:08 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 1AC0B6B0505; Fri, 17 Jan 2020 18:23:08 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 09A646B0506; Fri, 17 Jan 2020 18:23:07 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0154.hostedemail.com [216.40.44.154]) by kanga.kvack.org (Postfix) with ESMTP id E21DE6B0504 for ; Fri, 17 Jan 2020 18:23:07 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 8B6E1181AEF1A for ; Fri, 17 Jan 2020 23:23:07 +0000 (UTC) X-FDA: 76388704014.08.kick12_3851505173a23 X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,richardw.yang@linux.intel.com,:akpm@linux-foundation.org:dan.j.williams@intel.com:aneesh.kumar@linux.ibm.com:kirill@shutemov.name:yang.shi@linux.alibaba.com:richardw.yang@linux.intel.com:thellstrom@vmware.com:linux-kernel@vger.kernel.org:,RULES_HIT:30054:30070,0,RBL:134.134.136.31:@linux.intel.com:.lbl8.mailshell.net-62.18.0.100 64.95.201.95,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:26,LUA_SUMMARY:none X-HE-Tag: kick12_3851505173a23 X-Filterd-Recvd-Size: 4857 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by imf30.hostedemail.com (Postfix) with ESMTP for ; Fri, 17 Jan 2020 23:23:06 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Jan 2020 15:23:06 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,332,1574150400"; d="scan'208";a="306388163" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga001.jf.intel.com with ESMTP; 17 Jan 2020 15:23:04 -0800 From: Wei Yang To: akpm@linux-foundation.org, dan.j.williams@intel.com, aneesh.kumar@linux.ibm.com, kirill@shutemov.name, yang.shi@linux.alibaba.com, richardw.yang@linux.intel.com, thellstrom@vmware.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 2/5] mm/mremap: it is sure to have enough space when extent meets requirement Date: Sat, 18 Jan 2020 07:22:51 +0800 Message-Id: <20200117232254.2792-3-richardw.yang@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200117232254.2792-1-richardw.yang@linux.intel.com> References: <20200117232254.2792-1-richardw.yang@linux.intel.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: old_end is passed to these two function to check whether there is enough space to do the move, while this check is done before invoking these functions. These two functions only would be invoked when extent meets the requirement and there is one check before invoking these functions: if (extent > old_end - old_addr) extent = old_end - old_addr; This implies (old_end - old_addr) won't fail the check in these two functions. Signed-off-by: Wei Yang --- include/linux/huge_mm.h | 2 +- mm/huge_memory.c | 7 ++----- mm/mremap.c | 11 ++++------- 3 files changed, 7 insertions(+), 13 deletions(-) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 0b84e13e88e2..2a5281ca46c8 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -42,7 +42,7 @@ extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, unsigned char *vec); extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, - unsigned long new_addr, unsigned long old_end, + unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd); extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, pgprot_t newprot, diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 5b2876942639..8f1bbbf01f5b 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1871,17 +1871,14 @@ static pmd_t move_soft_dirty_pmd(pmd_t pmd) } bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, - unsigned long new_addr, unsigned long old_end, - pmd_t *old_pmd, pmd_t *new_pmd) + unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd) { spinlock_t *old_ptl, *new_ptl; pmd_t pmd; struct mm_struct *mm = vma->vm_mm; bool force_flush = false; - if ((old_addr & ~HPAGE_PMD_MASK) || - (new_addr & ~HPAGE_PMD_MASK) || - old_end - old_addr < HPAGE_PMD_SIZE) + if ((old_addr & ~HPAGE_PMD_MASK) || (new_addr & ~HPAGE_PMD_MASK)) return false; /* diff --git a/mm/mremap.c b/mm/mremap.c index bcc7aa62f2d9..c2af8ba4ba43 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -193,16 +193,13 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, #ifdef CONFIG_HAVE_MOVE_PMD static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr, - unsigned long new_addr, unsigned long old_end, - pmd_t *old_pmd, pmd_t *new_pmd) + unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd) { spinlock_t *old_ptl, *new_ptl; struct mm_struct *mm = vma->vm_mm; pmd_t pmd; - if ((old_addr & ~PMD_MASK) || - (new_addr & ~PMD_MASK) || - old_end - old_addr < PMD_SIZE) + if ((old_addr & ~PMD_MASK) || (new_addr & ~PMD_MASK)) return false; /* @@ -274,7 +271,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma, if (need_rmap_locks) take_rmap_locks(vma); moved = move_huge_pmd(vma, old_addr, new_addr, - old_end, old_pmd, new_pmd); + old_pmd, new_pmd); if (need_rmap_locks) drop_rmap_locks(vma); if (moved) @@ -294,7 +291,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma, if (need_rmap_locks) take_rmap_locks(vma); moved = move_normal_pmd(vma, old_addr, new_addr, - old_end, old_pmd, new_pmd); + old_pmd, new_pmd); if (need_rmap_locks) drop_rmap_locks(vma); if (moved)