From patchwork Wed Jan 29 00:26:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Yang X-Patchwork-Id: 11355383 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 B3A43159A for ; Wed, 29 Jan 2020 00:27:14 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 812932467E for ; Wed, 29 Jan 2020 00:27:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 812932467E 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 40E1A6B0006; Tue, 28 Jan 2020 19:27:13 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 396496B0008; Tue, 28 Jan 2020 19:27:13 -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 2ACD16B000A; Tue, 28 Jan 2020 19:27:13 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0204.hostedemail.com [216.40.44.204]) by kanga.kvack.org (Postfix) with ESMTP id 151666B0006 for ; Tue, 28 Jan 2020 19:27:13 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id D54C0485C for ; Wed, 29 Jan 2020 00:27:12 +0000 (UTC) X-FDA: 76428782304.15.eye47_5c012a03da324 X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,richardw.yang@linux.intel.com,:akpm@linux-foundation.org:aneesh.kumar@linux.ibm.com:kirill@shutemov.name:dan.j.williams@intel.com:yang.shi@linux.alibaba.com:thellstrom@vmware.com:richardw.yang@linux.intel.com:linux-kernel@vger.kernel.org::digetx@gmail.com,RULES_HIT:30054:30070,0,RBL:192.55.52.136:@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:24,LUA_SUMMARY:none X-HE-Tag: eye47_5c012a03da324 X-Filterd-Recvd-Size: 4882 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Wed, 29 Jan 2020 00:27:12 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Jan 2020 16:27:11 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,375,1574150400"; d="scan'208";a="229456097" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga003.jf.intel.com with ESMTP; 28 Jan 2020 16:27:09 -0800 From: Wei Yang To: akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, kirill@shutemov.name, dan.j.williams@intel.com, yang.shi@linux.alibaba.com, thellstrom@vmware.com, richardw.yang@linux.intel.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, digetx@gmail.com Subject: [Patch v2 2/4] mm/mremap: it is sure to have enough space when extent meets requirement Date: Wed, 29 Jan 2020 08:26:40 +0800 Message-Id: <20200129002642.13508-3-richardw.yang@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200129002642.13508-1-richardw.yang@linux.intel.com> References: <20200129002642.13508-1-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)